|This article is part of the series on the military of the Byzantine Empire, 330–1453 AD|
|Byzantine army (Generals): East Roman army, Middle Byzantine army (themes • tagmata • Hetaireia), Komnenian Byzantine army (pronoia), Palaiologan Byzantine army (allagia) • Varangian Guard|
|Byzantine navy (Admirals):Greek fire • Dromon|
|Lists of wars and revolts and civil wars|
|Strategy and tactics|
|Tactics • Siege warfare • Military manuals • Fortifications (Walls of Constantinople)|
The Hetaireia or Hetaeria (Ancient Greek: ἑταιρεία) was a corps of bodyguards of the Byzantine Empire. Its name means "the Company", echoing the ancient Macedonian Companion cavalry. The imperial Hetaireia, composed chiefly of foreigners, formed part of the Byzantine imperial guard alongside the tagmata in the 9th–12th centuries. This also included the smaller bodyguards of provincial generals (stratēgoi), headed by a count (Greek: κόμης τῆς ἑταιρείας komēs tēs hetaireias), and from the 13th century on, it was employed in a generic sense for the armed retinues of magnates, bound by oath to their master.
 History and role of the imperial Hetaireia
The exact origin, role, and structure of the imperial Hetaireia are unclear. The term first appears in the early 9th century: narrative sources record its existence in 813 as a bodyguard for the Byzantine emperor on campaign. John B. Bury theorized that it was the evolution of the earlier Foederati, but this supposition was rejected by John Haldon.
The Hetaireia of the middle Byzantine period was divided in several units: three or four according to the sources, distinguished by their epithets and each, at least originally, under is respective Hetaeriarch (ἑταιρειάρχης, hetaireiarchēs).
The senior unit was the "Great Hetaireia" (μεγάλη ἑταιρεία, megalē hetaireia), under the Great Hetaeriarch (megas hetaireiarchēs), who ranked as the senior of the military officials known as stratarchai and was often referred to simply as "the Hetaeriarch" (ὁ ἑταιρειάρχης) par excellence. It was a very important position in the late 9th and first half of the 10th centuries, as he was in charge of the Byzantine emperor's security, and was entrusted with delicate assignments. It is telling that the future emperor Romanos Lekapenos held this post, and was succeeded by his son Christopher Lekapenos. According to the mid-10th century De Ceremoniis, written by Emperor Constantine VII Porphyrogennetos (r. 913–959), the Great Hetaeriarch and his unit are charged with the protection of the emperor's tent on campaign, and with the security of the imperial palace, in close association with the papias of the palace.
A "Middle Hetaireia" (μέση ἑταιρεία, mesē hetaireia) is attested in sources, and the possible existence of a "Lesser Hetaireia" (μικρὰ ἑταιρεία, mikra hetaireia) is implied by the reference to Stylianos Zaoutzes as mikros hetaireiarchēs under Emperor Michael III (r. 842–867). Alternatively, the unit of the mikros hetaireiarchēs may be identical to the barbarian regiment composed of the two companies of the Chazaroi (Χαζάροι, "Khazars") and the Pharganoi (Φαργάνοι), which is called the "Third Hetaireia" (τρίτη ἑταιρεία, tritē hetaireia) in the Escorial Taktikon of circa 975. The historian Warren Treadgold estimates the total strength of the imperial Hetaireia in the early 10th century at 1,200 men.
The bulk of the Hetaireia was apparently composed of foreigners (ethnikoi), and contemporary accounts list Khazars, Pharganoi, Tourkoi (i.e. Magyars), Franks and Arabs. The meaning of the term Pharganoi has been the subject of debate. It could denote their origin from the area of Central Asia around the Fergana Valley, or it could be a misspelling of Pharangoi, i.e. Varangians. Honorary posts in the Hetaireia, however, were prestigious appointments that could be purchased by native Byzantine officials, connected to an annual stipend (roga) paid by the imperial treasury to the holder. A post in the "Great Hetaireia" cost a minimum of 16 litrai of gold, a post in the "Middle Hetaireia" a minimum of ten, and in each of the Chazaroi or Pharganoi companies a minimum of seven.
As the 10th century progressed, a tendency of amalgamation of the various units into a single command becomes evident, as the "Middle Hetaireia" seems to have been placed under the Great Hetaeriarch. The importance of the Hetaireia as a bodyguard corps declined thereafter, but the unit was one of the few regiments of the middle Byzantine army to survive into the Komnenian-era army, being attested well into the reign of Emperor Manuel I Komnenos (r. 1143–1180). By this time, however, its composition had changed: in the late 11th century, Nikephoros Bryennios the Younger reports that the Hetaireia was "customarily" made up of young Byzantine nobles.
The post of [megas] hetaireiarchēs also survived, and, detached from its military duties, remained an important court position: it was held by several influential palace eunuchs in the 11th century, and by second-rank nobles and junior relatives of the Byzantine imperial family, such as George Palaiologos, in the Komnenian period. In the Palaiologan period, it was held by members of prominent noble families.
 See also
- Treadgold 1995, pp. 100–105.
- Kazhdan 1991, p. 925.
- Oikonomides 2001, p. 12.
- Bury 1911, pp. 106–107.
- Haldon 1984, p. 246.
- Bury 1911, p. 106.
- Bury 1911, p. 108.
- Bury 1911, p. 107.
- Treadgold 1995, p. 110.
- Bury 1911, pp. 107–108; Oikonomides 2001, pp. 12, 27.
- Oikonomides 2001, pp. 20–21.
- Oikonomides 2001, pp. 17–18.
- Magdalino 2002, p. 321.
- Bury, John Bagnell (1911). The Imperial Administrative System of the Ninth Century - With a Revised Text of the Kletorologion of Philotheos. London, United Kingdom: Published for the British Academy by Henry Frowde, Oxford University Press.
- Haldon, John F. (1984). Byzantine Praetorians: An Administrative, Institutional and Social Survey of the Opsikion and Tagmata, c. 580–900. Bonn, Germany: R. Habelt. ISBN 3-7749-2004-4.
- Haldon, John F. (1999). Warfare, State and Society in the Byzantine World, 565-1204. London, United Kingdom: University College London Press (Taylor & Francis Group). ISBN 1-85728-495-X.
- Kazhdan, Alexander Petrovich, ed. (1991). The Oxford Dictionary of Byzantium. New York, New York and Oxford, United Kingdom: Oxford University Press. ISBN 978-0-19-504652-6.
- Magdalino, Paul (2002) . The Empire of Manuel I Komnenos, 1143–1180. Cambridge, United Kingdom: Cambridge University Press. ISBN 0-521-52653-1.
- Oikonomides, Nikos (2001). "Some Byzantine State Annuitants: Epi tes (Megales) Hetaireias and Epi ton Barbaron". Byzantina Symmeikta 14: 9–28. ISSN 1105-1639.
- Treadgold, Warren T. (1995). Byzantium and Its Army, 284–1081. Stanford, California: Stanford University Press. ISBN 0-8047-3163-2.
 Further reading
- Karlin-Hayter, Patricia (1974). "L'hétériarque. L'évolution de son rôle du "De Cerimoniis" au "Traité des Offices"". Jahrbuch der österreichischen Byzantinistik (in French) 23: 101–143.