Itineraries of the Roman emperors, 337–361
This article chronicles the attested movements of the fourth-century Roman emperors Constantine II (referred to here as Constantinus), Constantius II (referred to here as Constantius), Constans, Gallus, and Julian the Apostate from 337 to 361 CE. It does not cover the imperial usurpers of the period, including Magnentius, Vetranio, Claudius Silvanus, and Poemenius. The chronology is principally derived from classicist Timothy Barnes' Athanasius and Constantius.
This article begins its coverage at the death of Constantine on 22 May 337. After an interregnum of three months, during or after which the army and its agents lynched other potential successors, the three sons of Constantine declared themselves Augusti on 9 September 337. Discarding their father's succession arrangements, the brothers divided the empire into three parts.[notes 1] Constantinus ruled the provinces of Gaul, Britain, Spain, and Germany from Trier.[notes 2] Constantius ruled the provinces of Asia Minor (the dioceses of Pontus and Asia), Thrace, the Levant and Egypt (the Diocese of the East) from Antioch. Constans ruled Italy, Africa, and the dioceses of Pannonia, Dacia, and Macedonia from Naissus.
In 340, Constantinus attempted to seize his brother Constans' territory, and was killed in battle during the ensuing civil war. Constans acquired his territory, and ruled from Trier, Milan, and Sirmium. In January 350, Constans was overthrown and killed in a palace revolution instigated by Magnentius. Magnentius was defeated and killed in the summer of 353 at the Battle of Mons Seleucus, making Constantius the sole emperor.
From 351 to 359, Constantius ruled from Sirmium and Milan. Constantius appointed Gallus Caesar (subordinate emperor) on 15 March 351, and delegated the rule of the eastern provinces to him. Gallus ruled from Antioch. He subsequently proved violent and cruel, and was recalled and executed in autumn 354. Constantius appointed Julian, the last surviving male relative of Constantine other than himself, Caesar on 6 November 355. Julian ruled the western provinces from Vienne, Sens, and Paris. To address Persian influence and aggression on the eastern frontier, Constantius ruled from Antioch from 360 until his death.
Julian's troops proclaimed him Augustus in February 360. Constantius did not recognize Julian's claim to the title, but was detained from campaigning against him by Persian raids. Constantius died on 3 November 361 after declaring Julian his successor. Julian was sole emperor from Constantius' death until his own death in 363. This article ends its coverage at Julian's arrival in Constantinople on 11 December 361.
A † indicates that a date or an event is uncertain. A superscript S indicates that the manuscript is corrupt, and has been emended to follow Otto Seeck's corrections in his edition of the Codex Theodosianus. Manuscript details are given in brackets (as "mss. date" or "mss. year", etc.) for all emended texts. Unsourced events are purely conjectural.
|337, c. September||Confers with Constantius and Constans in Pannonia||Julian, Oratio 1, 19a, cf. Libanius, Oratio 59.75|
|338†||Campaigns in Germany||Corpus Inscriptionum Latinarum 3.12483 = Inscriptiones Latinae Selectae 724 + add. (3, p. clxxii);[notes 3] (Troesmis: 337/340)|
|8 January 339||At Trier†[notes 4]||Codex Theodosianus 12.1.27|
|Late winter 340||Invades the territory of Constans and is killed near Aquileia||Jerome, Chronicon 235a; Chronica minora 1.236; Epitome de Caesaribus 41.21; Socrates, Historia Ecclesiastica 2.5; Zonaras 13.5[notes 5]|
|July† 337[notes 6]||At Viminacium||Athanasius, Apologia ad Constantium 5.2|
|August/September† 337||Campaigns against the Sarmatae||Corpus Inscriptionum Latinarum 3.12483[notes 7]|
|337, c. September||Confers with Constantinus and Constans in Pannonia||Julian, Oratio 1.19a, cf. Libanius Orationes 59.75[notes 8]|
|September† 337||Returns to Constantinople||Socrates, Historia Ecclesiastica 2.7|
|November† 337[notes 9]||Returns to Antioch for the winter||Socrates, Historia Ecclesiastica 2.7, cf. Libanius Orationes 59.75, 66|
|Spring 338[notes 10]||At Caesarea in Cappadocia||Athanasius, Apologia ad Constantium 5.2|
|Restores Arsaces to the throne of Armenia||Julian, Oratio 1.20d–21a, cf. Libanius, Oratio 59,76–80|
|11 October 338||At Antioch||Codex Theodosianus 12.1.23|
|28 October 338||At Emesa||Codex Theodosianus 12.1.25|
|27 December 338||At Antioch||Codex Theodosianus 2.6.4|
|339, c. January||At Antioch||Athanasius, Epistula encyclica 2.1; Historia Arianorum 10.1|
|339 or 340||At Hierapolis||Papyri Abinnaeus 1.8–10[notes 11]|
|Summer 340||Invades Persian territory||Itinerarium Alexandri, pr. 1, cf. 4|
|12 August 340||At Edessa[notes 12]||Codex Theodosianus 12.1.30S (place of issue transmitted as Bessae)|
|9 September 340||At Antioch||Codex Theodosianus 6.4.5/6|
|6 January 341||Attends the 'Dedication Council' at Antioch[notes 13]||Athanasius, de Synodis 25.1; Philostorgius p. 212.19–22 Bidez|
|12 February 341||At Antioch||Codex Theodosianus 5.13.1/2|
|341/2||Winters in Antioch||Socrates, Historia Ecclesiastica 2.13.5, cf. Jerome Chronicon 235f; Chronica minora 1.236|
|Early 342||Visits Constantinople to expel the bishop Paul and returns to Antioch immediately after||Libanius, Oratio 59.94–97; Socrates, Historia Ecclesiastica 2.13.7, cf. Jerome Chronicon 235f; Chronica minora 1.236|
|31 March – 11 May 342||In Antioch||Codex Theodosianus 3.12.1; 12.1.33/4 (5, 8 April); 11.36.6|
|18 February 343||At Antioch||Codex Theodosianus 9.21.5|
|9 June – 4 July 343||In Hierapolis||Codex Theodosianus 8.1.1 (319 mss.); 12.1.35 (27 June); 15.8.1|
|Summer/autumn 343||Wins a victory over the Persians||Athanasius, Historia Arianorum 16.2, cf. Festus, Breviarium 27|
|October/November 343||Visits Constantinople†|
|344, c. April||At Antioch||Theodoret, Historia Ecclesiastica 2.8.56, 9.9–10, cf. Athanasius, Historia Arianorum 20.5|
|Summer 344†||Defeats the Persians near Singara||Julian, Oratio 1, 26a; Libanius, Oratio 59.88, 99–120; Jerome, Chronicon 236l; Chronica minora 1.236 (both Jerome and the Chronica minora give the date as 348), cf. Festus, Breviarium 27|
|345||At Nisibis||Codex Theodosianus 11.7.5, cf. Ephraem, Carmina Nisibena 13.4–6, 14/5|
|Summer 345||At Edessa||Athanasius, Apologia contra Arianos 51.6|
|21 March 346||At Antioch||Codex Theodosianus 10.14.1S (315 mss.)|
|346, c. September||At Antioch||Athanasius, Apologia ad Constantium 5.2; Historia Arianorum 44.5, Historia acephala 1.2; Festal Index 17; Jerome, Chronicon 236e|
|8 March 347||At Ancyra||Codex Theodosianus 11.36.8|
|347†, spring[notes 14]||Themistius delivers an imperial panegyric before Constantius at Ancyra[notes 15]||Themistius, Oratio 1|
|11 May 347||At Hierapolis†||Codex Theodosianus 5.6.1|
|348†, summer||Engages the Persians in battle near Singara||Festus, Breviarium 27|
|1 April 349||At Antioch||Codex Theodosianus 12.1.39|
|Summer 349||At Singara, then Emesa||Athanasius, Historia Arianorum 7.3|
|3 October 349||At Constantinople†||Codex Theodosianus 12.2.1 +15.1.6|
|Spring 350||At Edessa||Philostorgius, Historia Ecclesiastica 3.22|
|Summer 350||At Antioch while Shapur II besieges Nisibis||Theodoret, Historia Ecclesiastica 2.30.1, 9/10, 31.1|
|Visits Nisibis after the siege||Zonaras 13.7|
|Autumn 350||Leaves Antioch heading west||Philostorgius, p. 215.22–24 Bidez|
|Travels via Heraclea to Serdica||Zonaras 13.7|
|25 December 350||Engineers the abdication of Vetranio at Naissus||Jerome, Chronicon 238c (place and year); Chronica minora 1.238 (day, year falsely given as 351); Zosimus 2.44.3/4|
|15 March 351||Proclaims Gallus Caesar at Sirmium||Chronica minora 1.238|
|Summer and autumn 351||In Sirmium before and during the campaign against Magnentius||Sulpicius Severus, Chron. 2.38.5–7; Socrates, Historia Ecclesiastica 2.28.23; Zosimus 2.45.3, 48.3|
|351, October†||Present at the Council of Sirmium which deposed Photinus||Socrates, Historia Ecclesiastica 2.28.23, 29.1|
|26 February 352||At Sirmium||Codex Justinianus 6.22.5|
|12 May 352||At Sirmium||Codex Theodosianus 3.5.1S (319 mss.)|
|Summer 352||Campaign against the Sarmatae†|
|352, September†||Enters Italy||Chronica minora 1.67[notes 16]|
|3 November 352||At Milan||Codex Theodosianus 15.14.5|
|Spring–summer 353||In Milan||Historia acephala 1.7, cf. Festal Index 25; Codex Theodosianus 11.1.6 + 12.1.42 (22 May: year emended from 354), 16.8.7S (3 July: 357 mss.)|
|353, c. October – 354, Spring||Winters in Arles||Ammianus 14.5.1; Codex Theodosianus 8.7.2S (3 November: 326 mss.); Ammianus 14.10.1|
|Spring 354||At Valentia||Ammianus 14.10.1/2|
|Crosses the Rhine at Rauracum||Ammianus 14.10.6|
|Autumn 354 – spring 355||Winters in Milan||Ammianus 14.10.16; Codex Theodosianus 11.34.2 (1 January); Codex Justinianus 6.22.6 (18 February)|
|355, c. June||Conducts expedition into Raetia||Ammianus 15.4.1|
|Goes to winter quarters in Milan||Ammianus 15.4.13, cf. Sulpicius Severus, Chron. 2.39.3, 8 (Council of Milan)|
|6 July 355 – 5 July 356||In Milan||Codex Theodosianus 14.3.2; Codex Theodosianus 12.1.43 (17 July 355); 1.5.5 (18 July 355); 6.29.1 (22 July 355); 12.12.1 (1 August 355); 9.34.6 (31 October 355); 16.10.6 (19 February 356); 9.42.2 (8 March 356); 11.16.8S (1 April 356: 357 mss.); 11.16.7 (2 April 356); 6.4.8–10 (11 April 356); 6.29.2S (17 April 356: 357 mss.); 13.10.3S (29 April 356: 357 mss.); 9.17.4S = Codex Justinianus 9.19.4S (13 June 356: 357 mss.); Codex Theodosianus 8.5.8S (24 June 356: 357 mss.); 1.2.7 (5 July 356)|
|6 November 355||Proclaims Julian Caesar at Milan||Ammianus 15.8.17; Chronica minora 1.238; Corpus Inscriptionum Latinarum 12, p. 277; Socrates, Historia Ecclesiastica 2.34.5|
|1 December 355||Escorts Julian out of Milan, then returns to the city||Ammianus 15.8.18|
|Summer and autumn 356||Campaigns against the Alamanni on the Upper Rhine||Ammianus 16.12.15/6|
|25 July 356||At Messadensis[notes 17]||Codex Theodosianus 11.30.25S (355 mss.)|
|2 September 356||At Dinumma[notes 18]||Codex Theodosianus 11.7.8S (355 mss.)|
|10 November 356 – 19 March 357||In Milan||Codex Theodosianus 16.2.13S (357 mss.); 9.16.5S (4 December 356: 357 mss.); 8.7.7S (27 December: a date in 357 is implied); 12.12.2 (15 January 357); 9.17.4 (15 January 357: 'id.Iun.' mss.); 9.16.4 (25 January 357); 15.1.1S (2 February 357: 320 mss.); 10.20.2S (358 mss.)|
|28 April 357||Enters Rome||Chronica minora 1.239|
|28 April – 29 May 357||In Rome||Ammianus 16.10.20 (length of stay); Codex Theodosianus 8.1.5 (6 May 357); 10.1.2S (17 May 357: 319 mss.)|
|7 or 10 June 357||At Helvillum[notes 19]||Codex Theodosianus 1.5.6 + 7|
|5 July 357||At Ariminum||Codex Theodosianus 9.16.6S (358 mss.)|
|21 July 357||At Ravenna||Codex Theodosianus 12.1.40S (353 mss.)|
|Passes through Tridentum on the way to the Danube||Ammianus 16.10.20|
|Visits Pannonia and Moesia||Zosimus 3.2.2; Julian, Epistula ad SPQ Atheniarum 279d|
|October 357 – 3 March 358||Winters in Sirmium||Ammianus 16.10.21; 17.12.1; Codex Theodosianus 8.5.10 (27 October 357: transmitted year either 357 or 358); 1.15.3S (3 December 357: 353 mss.); 7.4.3, 11.30.27 (18 December 357); 2.21.2S (18 December 357: 360 mss.); 9.42.4 (4 January 357); Codex Justinianus 3.26.8|
|April 358||Invades the territory of the Sarmatae Limigantes||Ammianus 17.12.4–6|
|Returns in triumph to Sirmium||Ammianus 13.3.33|
|21–23 June 358||In Sirmium||Codex Theodosianus 12.1.44 + 45 (21 June 358); 8.13.4, 11.36.13 (23 June 358)|
|27 June 358||At Mursa||Codex Theodosianus 12.1.46|
|358, c. October – 359, c. March||Winters in Sirmium||Ammianus 18.4.1; 19.11.1; Codex Theodosianus 2.21.1 (19 December 358)|
|Spring 359||Begins a campaign against the Sarmatae||Ammianus 19.11.2|
|In the province of Valeria||Ammianus 19.11.4|
|Defeats the Limigantes near Acimincum||Ammianus 19.11.5–16|
|Returns to Sirmium||Ammianus 19.11.17|
|22 May 359||At Sirmium||Codex Theodosianus 6.4.14 + 15; Athanasius, de Synodicus 8.3; Socrates, Historia Ecclesiastica 2.37.18|
|28 May 359||At Sirmium||Codex Theodosianus 1.7.1|
|18 June 359||At Singidunum||Codex Theodosianus 11.30.28|
|†||At Adrianople†||Athanasius, de Synodicus 55.2/3 (implies intent to visit)|
|Autumn 359||Goes to Constantinople for the winter||Ammianus 19.11.17; 20.8.1; Socrates, Historia Ecclesiastica 2.41.1; Sozomen, Historia Ecclesiastica 4.23.3, cf. Chronica minora 1.239 (implies Constantius' presence in Constantinople before 11 December 359)|
|December 359 – March 360||In Constantinople||Sozomen, Historia Ecclesiastica 4.23.4–7 (late December 359 – 1 January 360); Hilary, Ad Constantium 2.2 (Corpus Scriptorum Ecclesiasticorum Latinorum 65.198.9/10), cf. Jerome, de Virus Illustribus 100; Codex Theodosianus 4.13.4S; 11.36.10S (18 January 360: 356 and 354 mss.); 11.24.1 (4 February 360); 14.1.1S (24 February 360: 357 mss.); 7.4.5S (14 March 360: 359 mss.)|
|360, March†||At Caesarea in Cappadocia, receiving news that Julian has been proclaimed Augustus||Ammianus 20.9.1|
|Travels via Melitene, Lacotena, and Samosata to Edessa||Ammianus 20.11.4|
|After 21 September, 360||Leaves Edessa||Ammianus 20.11.4|
|Visits Amida||Ammianus 20.11.4/5|
|Besieges Bezabde||Ammianus 20.11.6–31|
|17 December 360||At Hierapolis||Codex Theodosianus 7.4.6S (17 May mss.)|
|Late December 360 – 361, c. March||Winters in Antioch||Ammianus 20.11.32; Codex Theodosianus 16.2.16 (14 February 361); Socrates, Historia Ecclesiastica 2.45.10|
|3 May 361||At Gephyra||Codex Theodosianus 1.6.1, 28.1; 6.4.12, 13; 7.8.1; 11.1.7, 15.1, 23.1; 12.1.48; 13.1.3; 15.1.7 (all extracts from the same law)|
|29 May 361||At Doliche||Codex Theodosianus 7.4.4S (358 mss.: place of issue written as Doridae)|
|Crosses the Euphrates at Capersana, goes to Edessa, and later returns to Hierapolis (or perhaps Nicopolis)||Ammianus 21.7.7, 13.8|
|Autumn 361||Briefly returns to Antioch||Ammianus 21.15.1/2|
|October 361||At Hippocephalus||Ammianus 21.15.2|
|Falls ill at Tarsus||Ammianus 21.15.2|
|3 November 361||Dies at Mopsucrenae in Cilicia||Jerome, Chronicon 242b; Ammianus 21.15.3 (date emended from 5 October); Chronica minora 1.240; Socrates, Historia Ecclesiastica 2.47.4; 3.1.1|
|337, c. September||Confers with Constantinus and Constantius in Pannonia||Julian, Oratio 1, 19a, cf. Libanius, Oratio 59.75|
|6 December 337||At Thessalonica||Codex Theodosianus 11.1.4; 11.7.8S (353 mss.)|
|338/346[notes 20]||Campaign against the Sarmatae||Corpus Incriptionum Latinarum 3.12483|
|12 June 338||At Viminacium||Codex Theodosianus 10.10.4|
|27 July 338||At Sirmium||Codex Theodosianus 15.1.5; Codex Justinianus 10.48.7|
|339†, 6 April||At Savaria||Codex Theodosianus 10.10.6S (342 mss.)|
|19 January 340 – 2 February 340||At Naissus||Codex Theodosianus 12.1.29; 10.10.5|
|Hears of Constantinus' invasion of his territory while in Dacia||Zonaras 13.5|
|9 April 340||At Aquileia||Codex Theodosianus 2.6.5; 10.15.3|
|25 June 340||At Milan||Codex Theodosianus 9.17.1|
|340†||Visits Rome†||Passio Artemii 9 = Philostorgius, Historia Ecclesiastica 3.1A|
|24 June 341||At Lauriacum||Codex Theodosianus 8.2.1 = 12.1.31|
|Late 341||Campaigns against the Franci in Gaul||Jerome, Chronicon 235b; Chronica minora 1.236|
|342||Wins a victory over the Franci and signs a treaty with them||Libanius, Oratio 59.127–136; Jerome, Chronicon 235e; Chronica minora 1.236; Socrates, Historia Ecclesiastica 2.13.4|
|Summer 342||In Trier||Socrates, Historia Ecclesiastica 2.18|
|Autumn 342||Interviews Athanasius in Milan||Athanasius, Apologia ad Constantium 4.3|
|4 December 342||At Milan||Codex Theodosianus 9.7.3|
|25 January 343||At Bononia||Codex Theodosianus 11.16.5, cf. Codex Justinianus 3.26.6|
|Crosses to Britain in winter||Firmicus Maternus, De errore profanarum religionum 28.6; Libanius, Oratio 59.137–140; Ammianus 20.1.1|
|Spring 343||Returns from Britain to Gaul soon after his departure||Libanius, Oratio 59.139, 141|
|30 June 343||At Trier||Codex Theodosianus 12.1.36|
|Summer 343||Interviews Athanasius in Trier||Athanasius, Apologia ad Constantium 4.4, cf. 3.7|
|Autumn 344||In Pannonia||Libanius, Oratio 59.133|
|Early 345||Receives an embassy from Constantius at Poetovio||Athanasius, Apologia ad Constantium 3.3|
|7 April 345||At Aquileia at Easter, where he interviews Athanasius||Athanasius, Apologia ad Constantium 15.4, cf. 3.7; Festal Index 17|
|15 May 345||At Trier||Codex Theodosianus 10.10.7|
|9 June or 11 July 345||At Cologne||Codex Theodosianus 3.5.7|
|Autumn† 345||Interviews Athanasius in Trier||Athansius, Apologia ad Constantium 4.5, cf. 3.7|
|346†, 5 March||At Sirmium||Codex Theodosianus 10.10.8S (353 mss.)|
|23 May 346||At Caesena||Codex Theodosianus 12.1.38|
|17 June 348||At Milan||Codex Theodosianus 10.14.2|
|27 May 349||At Sirmium||Codex Theodosianus 7.1.2 + 8.7.3|
|350, shortly after 18 January||Killed at Helena in Gaul||Eutropius, Breviarium 10.9.4; Jerome, Chronicon 237c; Chronica minora 1.237; Epitome de Caesaribus 41.23; Zosimus 2.42.5|
|15 March 351||Proclaimed Caesar at Sirmium||Chronica minora 1.238 (day); Passio Artemii 12 = Philostorgius, Historia Ecclesiastica 3.26a|
|7 May 351||Reaches Antioch||Socrates, Historia Ecclesiastica 2.28.22|
|Campaigns in Mesopotamia†||Philostorgius, Historia Ecclesiastica 3.28|
|Summer 352||Suppresses a Jewish rebellion in Galilee||Jerome, Chronicon 238f|
|Late summer 353 – spring 354||At Antioch||Ammianus 14.1.4–9, 7.1–4|
|354, c. March||Visits Hierapolis||Ammianus 14.7.5|
|354, c. 1 September||Leaves Antioch||Ammianus 14.11.12|
|14–30 September 354||At Nicomedia†||Papyri Laurentius 169 (consular date of 354 restored)|
|Stripped of his imperial rank at Poetovio||Ammianus 14.11.19/20|
|October 354||Tried and executed near Pola||Ammianus 14.11.20–30|
|6 November 355||Proclaimed Caesar at Milan||Ammianus 15.8.7; Corpus Inscriptionum Latinarum 12, p. 277; Chronica minora 1.238; Socrates, Historia Ecclesiastica 2.34.5|
|6–30 November 355||At Milan||Ammianus 15.8.18|
|1 December 355||Leaves Milan||Ammianus 15.8.18|
|Travels via Turin to Vienne||Ammianus 15.8.18–21|
|December 355 – spring 356||At Vienne||Ammianus 16.1.1, 2.1|
|April/May 356||Present at the Council of Baeterrae†||Hilary, Ad Constantium 2 (Corpus Scriptorum Ecclesiasticorum Latinorum 65.198.5–15)|
|24 June 356||Reaches Autun||Ammianus 16.2.2|
|Passes through Auxerre||Ammianus 16.2.5|
|Advances via Troyes, Reims, Decem Pagi, Brotomagus||Ammianus 16.2.6–8|
|356, c. August||Recaptures Cologne||Ammianus 16.3.1/2, cf. Julian, Epistula ad SPQ Atheniarum 279b|
|Visits Trier||Ammianus 16.3.3|
|356/7||Winters at Sens||Ammianus 16.3.3, 7.1, 11.1|
|Spring 357||Goes to Reims||Ammianus 16.11.1|
|Marches toward Strasbourg and wins a victory over the Alamanni||Ammianus 16.11.8–12.67|
|Returns to Tres Tabernae||Ammianus 17.1.1|
|Goes to Mainz||Ammianus 17.1.2|
|Conducts raid across the Rhine||Ammianus 17.1.2/3|
|December 357 – January 358||Besieges barbarians at a fortified town on the Meuse for 54 days||Ammianus 17.2.2/3|
|January–July 358||Winters in Paris||Ammianus 17.2.4, 8.1|
|July–autumn 358||Campaigns against the Salian Franci in Toxandria||Ammianus 17.8.3–10.10|
|1 January 359||In winter quarters at Paris||Ammianus 18.1.1|
|Strengthens the Rhine frontier from Castra Herculis to Bingen||Ammianus 18.2.4|
|Crosses the Rhine from Mainz and conducts a raid into German territory||Ammianus 18.2.7–19|
|1 January 360||In winter quarters at Paris||Ammianus 20.1.1|
|360, February†||Proclaimed Augustus at Paris||Julian, Epistula ad SPQ Atheniarum 283a–285a; Ammianus 20.4.4–22; Zosimus 3.9.1–3|
|Summer 360||Crosses the Rhine at Tricesima and attacks the Franci Attuarii||Ammianus 20.10.1/2|
|Autumn 360||Marches up the left bank of the Rhine to Rauracum, then via Besançon to Vienne||Ammianus 20.10.3|
|6 November 360 – 361, c. March||Winters at Vienne||Ammianus 20.10.3; 21.1 (6 November 360); 21.2.5 (6 January 361), 3.1|
|Spring 361||Attacks Germans, crosses the Rhine, and goes to Rauracum||Ammianus 21.3.3–4.8, 8.1|
|Leaves Rauracum, advances up the Rhine, then down the Danube||Ammianus 21.8.1–10.2|
|Mid-July 361||Continues advancing down the Danube via Sirmium as far as the Pass of Succi||Ammianus 21.8.1–10.2|
|Returns to Naissus||Ammianus 21.20.5|
|At Naissus||Ammianus 21.12.1; Zosimus 3.11.2|
|After receiving news of Constantius' death, leaves Naissus and travels via Philippopolis and Heraclea/Perinthus to Constantinople||Ammianus 21.12.3; 22.2|
|11 December 361||Enters Constantinople||Ammianus 22.2.4; Chronica minora 1.240; Socrates, Historia Ecclesiastica 3.1.2|
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- Historia Arianorum (History of the Arians). 357.
- Atkinson, M., and Archibald Robertson, trans. Historia Arianorum. From Nicene and Post-Nicene Fathers, Second Series, Vol. 4. Edited by Philip Schaff and Henry Wace. Buffalo, NY: Christian Literature Publishing Co., 1892. Revised and edited for New Advent by Kevin Knight. Online at New Advent. Accessed 14 August 2009.
- De Synodis (On the Councils of Arminium and Seleucia). Autumn 359.
- Newman, John Henry and Archibald Robertson, trans. De Synodis. From Nicene and Post-Nicene Fathers, Second Series, Vol. 4. Edited by Philip Schaff and Henry Wace. Buffalo, NY: Christian Literature Publishing Co., 1892. Revised and edited for New Advent by Kevin Knight. Online at New Advent. Accessed 15 August 2009.
- Historia acephala. 368 – c. 420.
- Robertson, Archibald, trans. Historia Acephala. From Nicene and Post-Nicene Fathers, Second Series, Vol. 4. Edited by Philip Schaff and Henry Wace. Buffalo, NY: Christian Literature Publishing Co., 1892. Revised and edited for New Advent by Kevin Knight. Online at New Advent and Christian Classics Ethereal Library. Accessed 15 August 2009.
- Chronica minora 1, 2.
- Codex Theodosianus.
- Mommsen, T. and Paul M. Meyer, eds. Theodosiani libri XVI cum Constitutionibus Sirmondianis et Leges novellae ad Theodosianum pertinentes2 (in Latin). Berlin: Weidmann,  1954. Complied by Nicholas Palmer, revised by Tony Honoré for Oxford Text Archive, 1984. Prepared for online use by R.W.B. Salway, 1999. Preface, books 1–8. Online at University College London and the University of Grenoble. Accessed 25 August 2009.
- Unknown edition (in Latin). Online at AncientRome.ru. Accessed 15 August 2009.
- Codex Justinianus.
- Scott, Samuel P., trans. The Code of Justinian, in The Civil Law. 17 vols. 1932. Online at the Constitution Society. Accessed 14 August 2009.
- Ephraem the Syrian. Carmina Nisibena (Songs of Nisibis).
- Stopford, J.T. Sarsfield, trans. The Nisibene Hymns. From Nicene and Post-Nicene Fathers, Second Series, Vol. 13. Edited by Philip Schaff and Henry Wace. Buffalo, NY: Christian Literature Publishing Co., 1890. Revised and edited for New Advent by Kevin Knight. Online at New Advent. Accessed 16 August 2009.
- Bickell, Gustav, trans. S. Ephraemi Syri Carmina Nisibena: additis prolegomenis et supplemento lexicorum Syriacorum (in Latin). Lipetsk: Brockhaus, 1866. Online at Google Books. Accessed 15 August 2009.
- Epitome de Caesaribus.
- Banchich, Thomas M., trans. A Booklet About the Style of Life and the Manners of the Imperatores. Canisius College Translated Texts 1. Buffalo, NY: Canisius College, 2009. Online at De Imperatoribus Romanis. Accessed 15 August 2009.
- Eusebius of Caesarea.
- Oratio de Laudibus Constantini (Oration in Praise of Constantine, sometimes the Tricennial Oration).
- Richardson, Ernest Cushing, trans. Oration in Praise of Constantine. From Nicene and Post-Nicene Fathers, Second Series, Vol. 1. Edited by Philip Schaff and Henry Wace. Buffalo, NY: Christian Literature Publishing Co., 1890. Revised and edited for New Advent by Kevin Knight. Online at New Advent. Accessed 16 August 2009.
- Vita Constantini (Life of Constantine).
- Richardson, Ernest Cushing, trans. Life of Constantine. From Nicene and Post-Nicene Fathers, Second Series, Vol. 1. Edited by Philip Schaff and Henry Wace. Buffalo, NY: Christian Literature Publishing Co., 1890. Revised and edited for New Advent by Kevin Knight. Online at New Advent. Accessed 25 August 2009.
- Festus. Breviarium.
- Banchich, Thomas M., and Jennifer A. Meka, trans. Breviarium of the Accomplishments of the Roman People. Canisius College Translated Texts 2. Buffalo, NY: Canisius College, 2001. Online at De Imperatoribus Romanis. Accessed 15 August 2009.
- Firmicus Maternus. De errore profanarum religionum (On the error of profane religions).
- Baluzii and Rigaltii, eds. Divi Cæcilii Cypriani, Carthaginensis Episcopi, Opera Omnia; accessit J. Firmici Materni, Viri Clarissimi, De Errore Profanarum Religionum (in Latin). Paris: Gauthier Brothers and the Society of Booksellers, 1836. Online at Google Books. Accessed 15 August 2009.
- Hilary of Poitiers. Ad Constantium (To Constantius).
- Feder, Alfred Leonhard, ed. S. Hilarii episcopi Pictaviensis Tractatus mysteriorum. Collectanea Antiariana Parisina (fragmenta historica) cum appendice (liber I Ad Constantium). Liber ad Constantium imperatorem (Liber II ad Constantium). Hymni. Fragmenta minora. Spuria (in Latin). In the Corpus Scriptorum Ecclesiasticorum Latinorum, Vol. 65. Vienna: Tempsky, 1916.
- Itinerarium Alexandri (Itinerary of Alexander).
- Chronicon (Chronicle).
- Pearse, Roger, et al., trans. The Chronicle of St. Jerome, in Early Church Fathers: Additional Texts. Tertullian, 2005. Online at Tertullian. Accessed 14 August 2009.
- de Viris Illustribus (On Illustrious Men).
- Richardson, Ernest Cushing, trans. De Viris Illustribus (On Illustrious Men). From Nicene and Post-Nicene Fathers, Second Series, Vol. 3. Edited by Philip Schaff and Henry Wace. Buffalo, NY: Christian Literature Publishing Co., 1892. Revised and edited for New Advent by Kevin Knight. Online at New Advent. Accessed 15 August 2009.
- Libanius. Oratio 59 (Oration 59).
- Origo Constantini Imperatoris.
- Rolfe, J.C., trans. Excerpta Valesiana, in vol. 3 of Rolfe's translation of Ammianus Marcellinus' History. Loeb ed. London: Heinemann, 1952. Online at LacusCurtius. Accessed 16 August 2009.
- Papyri Abinnaeus.
- Papyri Laurentius.
- Philostorgius. Historia Ecclesiastica.
- Walford, Edward, trans. Epitome of the Ecclesiastical History of Philostorgius, Compiled by Photius, Patriarch of Constantinople. London: Henry G. Bohn, 1855. Online at Tertullian. Accessed 15 August 2009.
- Socrates. Historia Ecclesiastica (History of the Church).
- Zenos, A.C., trans. Ecclesiastical History. From Nicene and Post-Nicene Fathers, Second Series, Vol. 2. Edited by Philip Schaff and Henry Wace. Buffalo, NY: Christian Literature Publishing Co., 1890. Revised and edited for New Advent by Kevin Knight. Online at New Advent. Accessed 14 August 2009.
- Sozomen. Historia Ecclesiastica (History of the Church).
- Sulpicius Severus. Sacred History.
- Roberts, Alexander, trans. Sacred History. From Nicene and Post-Nicene Fathers, Second Series, Vol. 11. Edited by Philip Schaff and Henry Wace. Buffalo, NY: Christian Literature Publishing Co., 1894. Revised and edited for New Advent by Kevin Knight. Online at New Advent. Accessed 14 August 2009.
- Theodoret. Historia Ecclesiastica (History of the Church).
- Jackson, Blomfield, trans. Ecclesiastical History. From Nicene and Post-Nicene Fathers, Second Series, Vol. 3. Edited by Philip Schaff and Henry Wace. Buffalo, NY: Christian Literature Publishing Co., 1892. Revised and edited for New Advent by Kevin Knight. Online at New Advent. Accessed 15 August 2009.
- Themistius. Orationes (Orations).
- Zosimus. Historia Nova (New History).
- Unknown trans. The History of Count Zosimus. London: Green and Champlin, 1814. Online at Tertullian. Accessed 15 August 2009. [An unsatisfactory edition.]
- Unknown trans. Histoire Nouvelle and ΖΩΣΙΜΟΥ ΚΟΜΙΤΟΣ ΚΑΙ ΑΠΟΦΙΣΚΟΣΥΝΗΓΟΡΟΥ (in French and Greek). Online at the Catholic University of Louvain. Accessed 16 November 2009.
- Barnes, Timothy D. "Imperial Chronology, A.D. 337–350." Phoenix 34:2 (1980): 160–66.
- Barnes, Timothy D. "The Career of Abinnaeus." Phoenix 39:4 (1985): 368–74.
- Barnes, Timothy D. "Ammianus Marcellinus and His World." Classical Philology 88:1 (1993): 55–70.
- Barnes, Timothy D. Athanasius and Constantius: Theology and Politics in the Constantinian Empire. Cambridge, MA: Harvard University Press, 1993.
- Callu, Jean-Paul. "Un 'Miroir des Princes': Le 'Basilikos' libanien de 348" (in French). Gerión 5 (1987): 133–52. Online at the Universidad Complutense Madrid.
- Jones, A.H.M. The Later Roman Empire 284–602: A Social, Economic, and Administrative Survey. London: Basil Blackwell, 1964, 3 vols.; rept. Baltimore: Johns Hopkins, 1986, 2 vols.
- Matthews, John. The Roman Empire of Ammianus. London: Duckworth, 1989.
- Heather, Peter, and David Moncur, ed. and trans. Politics, Philosophy, and Empire in the Fourth Century: Selected Orations of Themistius. Liverpool: Liverpool University Press, 2002.
- Seeck, Otto. Die Briefe des Libanius zeitlich geordnet (in German). Leipzig: J.C. Hinrichs, 1906. Online at the Internet Archive. Accessed 5 November 2009.
- Vanderspoel, John. Themistius and the Imperial Court: Oratory, Civic Duty, and Paideia from Constantius to Theodosius. Ann Arbor: University of Michigan Press, 1995.
- The original succession plan would have had Dalmatius rule the dioceses of Thrace, Macedonia, and Hannibalianus rule Armenia and neighboring allied nations. Both were now dead.
- Constantinus had ruled from Trier before 337 as well.
- Constantius' titles in the inscription are Al[aman(nicus) ma]x. G[erm(anicus) max.], whereas he was merely Alaman(nicus) in an inscription dated to c. February 337, implying that he won a victory over the Germans in a campaign in spring 337 or after.
- The Codex Theodosianus 12.1.27 is a constitution addressed to Aurelius Celsinus, proconsul of Africa, which was not formally within Constantinus' dominions, but Constantius'. The accuracy of the letter's date has therefore been challenged. Aurelius Celsinus was, however, proconsul of Africa from 337 to 340 (Corpus Inscriptionum Latinarum 8.12272), and so the constitution may thus represent an attempt by Constantinus to assert his self-proclaimed primacy in the imperial college.
- Zosimus (2.41) falsely describes Constans as the aggressor.
- Barnes elsewhere dates this event—Athanasius' meeting with Constantius—to c. August. After the meeting, Athanasius left Viminacium and traveled to Alexandria by way of Constantinople. He arrived on 23 November 337.
- The inscription, dated to 340, shows that Constantius took the title Sarmaticus at some time between 337 and that year.
- Jean-Paul Callu dates the meeting between Constantius and Constans to which Libanius refers to 340, after Constantinus' death, since Libanius is otherwise silent on the "triarchic period".
- Barnes' earlier date for this event was "337, late".
- Barnes was less confident about this dating in his "Imperial Chronology", where it was marked with a "?". Barnes argues for the spring dating, without confirmatory data, on the basis of the itineraries of Athanasius and Constantius in this period.
- According to his papers, Abinnaeus visited the imperial court at Hierapolis with recruits from the Thebaid. The meeting occurred between two events whose date is known: on the one hand, Abinnaeus' earlier travels with the Blemmyes from Egypt's southern border to the Bosphorus, and, on the other, his command at Dionysias. Abinnaeus is attested at Dionysias from 29 March 342. Barnes, from Eusebius' Vita Constantini, deduces that the trip to Constantinople with the Blemmyes occurred in the summer of 336. Since Constantius' precise whereabouts are not known for any point between 27 December 338 and 12 August 340, Barnes dates the emperor's meeting with Abinnaeus to this period.
- Barnes was less confident about this identification in his "Imperial Chronology," where it was written as "Edessa?".
- Barnes cites W. Elteser, Zeitschrift für die neutestamentliche Wissenschaft und die Kunde der alten Kirche 36 (1937) 254f. on the date; E. Schwartz, Zeitschrift für die neutestamentliche Wissenschaft und die Kunde der alten Kirche 34 (1935) 142, had dated the council to autumn 341.
- A date of c. 350 is also possible. Like most contemporary panegyrics, the Oratio 1 makes few overt references to political events. Richard Foerster, the compiler of the modern edition of Libanius' works, Libanii Opera (1903), argued for a date in the 340s on the belief that Libanius wrote his Oratio 59 after seeing Themistius' speech. Foerster dated Oratio 59 to 348/9, a dating most scholars have since followed. Foerster adduced the attestation at Ancyra (where the speech was known to have been delivered) in the Codex Theodosianus 11.36.8 (see entry above) in favor of a 347 date. In response to Foerter's view, Otto Seeck argued that since Constans is not mentioned, it must have been delivered after his death. The attestation in the Codex Theodosianus was not decisive, since Constantius would have passed Ancyra whenever he traveled through Asia Minor. Given that the only other date Constantius could had traveled along this path was in the autumn of 350, Seeck held that to be the only other plausible dating. Most twentieth-century scholars followed Seeck. Barnes and the scholar John Vanderspoel take the 347 date. Although Barnes considers Foerster's premise on Themistius' influence on Libanius "erroneous", the absence of any remarks on the usurpations in the west makes a 350 dating untenable. Vanderspoel argues that Themistius' allusion to the destruction of the Persian king by "the virtue of the emperor shining nearby", when compared with the catalog of Roman victories against the Persians that occurred while Constantius was merely nearby, and not personally involved, points to a date between the two sieges of Singara in 346 and 348.
- Callu, following H. Scholze, has noted that the localization in Ancyra is given only in the title of the oration, and is thus of dubious value.
- Naeratius Cerealis became praefectus urbi on 27 September 352. Constantius would have been in attendance.
- Messadensis is otherwise unknown.
- Dinumma is otherwise unknown.
- The manuscripts record both Haerbillio and Med[iolani]. Mommsen (in his edition of the Codex Theodosianus at 1.5.6 + 7) identified the location as Helvillum on the Via Flaminia between Spoletium and Ariminum.
- The Prosopography of the Later Roman Empire, following Gothofredus and Mommsen, emends the year to 346.
- Barnes, Athanasius, 310 n. 3, with the note that Poemenius probably never claimed the title of Augustus.
- Barnes, Athanasius, 218–28.
- Jones, The Later Roman Empire, 112.
- Barnes, "Imperial Chronology," 160.
- Epitome de Caesaribus 41.20; Origo Constantini Imperatoris 35; Barnes, "Imperial Chronology," 160.
- Jones, Later Roman Empire, 112; Barnes, Athanasius, 218.
- Barnes, "Imperial Chronology," 161, citing Eusebius, Triac. 3.4.
- Jones, Later Roman Empire, 112; Barnes, Athanasius, 219.
- Jones, Later Roman Empire, 112; Barnes, Athanasius, 224.
- Jones, Later Roman Empire, 112–13; Barnes, Athanasius, 224.
- Jones, Later Roman Empire, 112–13.
- Barnes, Athanasius, 219.
- Barnes, Athanasius, 226.
- Jones, Later Roman Empire, 116.
- Jones, Later Roman Empire, 117.
- Ammianus 21.15.3. John Matthews, The Roman Empire of Ammianus (London: Duckworth, 1989), 101, treats the account with skepticism: "Whether truthfully or by a useful fiction, he was said while his mind was still lucid to have named Julian as his successor." The date is that of Jones (Later Roman Empire, 120) and Barnes (Athanasius, 224). See table; Barnes, "Ammianus Marcellinus," 64–65.
- Matthews, Ammianus, 105.
- Barnes, Athanasius, 228.
- Barnes, "Imperial Itineraries," 161.
- Barnes, "Imperial Chronology," 161 n. 8, citing Année Épigraphique 1934.158.
- Barnes, "Imperial Chronology," 161 n. 8, citing idem. "The Victories of Constantine," Zeitschrift für Papyrologie und Epigraphik 20 (1976): 149–55.
- Barnes, Athanasius, 310–11 n. 4, citing and reproducing the inscription in E. Popescu, Inscripţiile greceşti şi latine din secolele IV–XIII descoperite în România (Bucarest, 1976), 251 no. 238.
- Barnes, Athanasius, 311 n. 5.
- Barnes, "Imperial Chronology," 161 n. 9.
- Barnes, "Imperial Chronology," 162 n. 11; cf. Athanasius, 219.
- Festal Index 10; Barnes, Athanasius, 311 n. 8.
- Barnes, "Imperial Chronology," 162 n. 10.
- Callu, 138 n. 26.
- Barnes, "Imperial Chronology," 162.
- Barnes, Athanasius, 42.
- Papyri Abinnaeus 44; Barnes, "Abinnaeus," 369, 370.
- Eusebius, Vita Constantini 4.7.1 (July 336); Barnes, "Abinnaeus," 369–70.
- See table.
- Barnes, "Abinnaeus," 370.
- Barnes, "Imperial Chronology," 163.
- Heather and Moncur, 43; Vanderspoel, 71–77.
- Heather and Moncur, 43.
- Vanderspoel, 73, citing Foerster, Libanii Opera (1903), 4.201–2.
- Callu, 136 n. 18, citing G. Dagron, "L'Empire au IVe S. et les traditions politiques de l'héllenisme," in Travaux et Mémoires 3 (1968), 20 n. 9.
- Vanderspoel, 73, citing Otto Seeck, Die Briefe des Libanius zeitlich geordnet (Leipzig, 1906), 293–94.
- Barnes, Athanasius, 313 n. 21; Vanderspoel, Themistius, 73.
- Barnes, Athanasius, 220, 313 n. 21; Vanderspoel, Themistius, 76–77.
- Barnes, Athanasius, 313 n. 21.
- Themistius, Oratio 1.12a–b, qtd. and tr. Vanderspoel, 74.
- Vanderspoel, 75–76.
- Callu, 135–36, citing H. Scholze, De temporibus librorun Themistii (Göttingen, 1911), 9–11.
- Barnes, Athanasius, 221.
- Barnes, Athanasius, 314 n. 34.
- Barnes, Athanasius, 314 n. 36.
- Barnes, Athanasius, 315 n. 45, citing A.H.M. Jones, J.R. Martindale, and J. Morris, The Prosopography of the Later Roman Empire 1: A.D. 260–395 (Cambridge: Cambridge University Press, 1971), 764.
- Barnes, Athanasius, xi.
- Barnes, Athanasius, xii.
- Barnes, Athanasius, 4.