Latin Rights (Latin: ius Latii or ius latinum) was a term for a set of legal rights that was originally granted to the Latins (Latin: "Latini", the People of Latium, the land of the Latins) who had not been incorporated into the Roman Republic after the Latin War and to the settlers of Roman colonies with Latin status, which colonies were denominated "Latin colonies".
The definition of the term changed as a result of three laws which were introduced during the Social War between the Romans and their allies among the Italic peoples ("socii") which rebelled against Rome. The Lex Iulia de Civitate Latinis (et sociis) Danda of 90 BC conferred Roman citizenship on all citizens of the Latin towns and the Italic towns who had not rebelled. The Lex Plautia Papiria de Civitate Sociis Danda of 89 BC granted Roman citizenship to all federated towns in Italy south of the River Po (in northern Italy). The Lex Pompeia de Transpadanis of 89 BC granted the ius Latii to the communities of Transpadania, a region north of the Po, which had sided with Rome during the Social War. It also granted Roman citizenship to those who became officials in their respective municipia (cities). This introduced a status that was intermediate between that of Roman citizen and foreigner ("peregrinus"). Prior to that, peregrini comprised the Latini, socii (Italic allies), and provinciales (Roman subjects outside Italy). "Latinitas" became commonly used by Roman jurists to denote this status. Cicero used this term in relation to Julius Caesar's grant of Latin rights to the Sicilians in 44 BC.  This use of "ius Latii" or "Latinitas" persisted to the reign of Emperor Justinian I in the sixth century AD. This status was later given to whole towns and regions: Emperor Vespasian granted it to the whole of Hispania and Emperor Hadrian gave it to many towns.
The ius Latii included, under Roman law), the:
- Ius commercii: the right to trade, i. e., the right to have commercial relations and trade with Roman citizens on equal status and to use the same forms of contract as Roman citizens;
- Ius connubii: the right to marry pursuant to law; and
- Ius migrationis: the right to migrate, i. e., the right to retain one’s degree of citizenship upon relocation to another municipium; in other words, Latin status was not lost when moving to other locales in Italy.
From 340 to 338 BC the Latin League, a confederation of circa 30 towns in Latium (land of the Latins) which was allied with Rome, rebelled in what has been called the Latin War. The Romans won the war and dissolved the Latin League. Many of the city-states of Latium were fully incorporated into the Roman Republic, while others were given limited rights and privileges which could be exercised in dealings with Roman citizens. These came to be known as ius Latii. The ius Latii was given to some Roman colonies which were founded around Italy in the fourth and third centuries BC to strengthen Roman control, as Rome expanded its hegemony over the peninsula. They were colonies which were given Latin legal status, and their settlers the ius Latii, instead of the Roman legal status of other colonies whose their settlers were given Roman citizenship. Colonies of Latin status were called "Latin colonies" and those of Roman status were called "Roman colonies". Roman citizens who settled in a Latin colony lost their Roman citizenship and acquired ius Latii. Latin colonies were usually smaller than Roman colonies.
In 122 BC, the plebeian tribune Gaius Gracchus introduced a law which extended the ius Latii to all other residents of Italy. This reflected the increasing ties between Rome and the Italic peoples through trade and the ties between the leading families in the Italian towns and patrician families in Rome. With Roman expansion beyond Italy, Latin colonies were also founded outside Italy, e. g. Carteia (contemporary San Roque), which was founded in Hispania in 171 BC and was the first Latin colony outside of Italy. In 44 BC, Julius Caesar granted the ius Latii to all free-born Sicilians.
Under the Empire
Following the great spat of colonial settlements under Julius Caesar and Augustus, the ius Latii was used more as a political instrument that aimed at integration of provincial communities via their local leadership. Latin status included the acquisition of Roman citizenship upon the holding of municipal magistracy (ius adipiscendae civitatis per magistratum), which presumed a trajectory of development that would carry at least the local magistrates along the path to the institution of a Roman-style community. In AD 123, Emperor Hadrian made a key modification to Latin rights. He introduced "Latium maius" ("greater Latin [rights]"), which conferred Roman citizenship on all the decurions of a town as opposed to "Latium minus", which conferred it only on those who held a magistracy. 
The acquisition of ius Latii was wholly dependent on imperial gift. This beneficence could span the whole range from grants to individuals to awards made to whole towns, and could even be applied to an entire population, as when Emperor Vespasian gave the ius Latii to all of Hispania in AD 74. Although this decree could encompass whole cities, it is important to note that it did not necessarily entail the establishment of a municipium (self-governing town). Often, as in Hispania, formal municipia might have been constituted several years after the initial grant.
- "Latinitas" also means "purity of language", that is, the use of "good Latin" or "correct Latin", equivalent to hellenismos; see for instance Laurent Pernot, Rhetoric in Antiquity (The Catholic University of America Press, 2005), p. 103 online; Richard Leo Enos, "Rhetorica ad Herennium", in Classical Rhetorics and Rhetoricians (Greenwood, 2005), p. 332 online; John Richard Dugan, Making a New Man: Ciceronian Self-Fashioning in the Rhetorical Works (Oxford University Press, 2005), passim; Brian A. Krostenko, Cicero, Catullus, and the Language of Social Performance (University of Chicago Press, 2001), p. 123 online.
- Cicero, ad Atticus, 14, 12.
- Pliny the Elder, Natural History, 3, 4.
- Historia Augusta, The Life of Hadrian, 21.
- Some of the material for this paragraph is from Smith's Dictionary of Greek and Roman Antiquities.
- Pearson, M., Perils of Empire: The Roman Republic and the American Republic (2008), p. 210
- Wilson, R. J. A., "Sicily, Sardinia and Corsica", in Bowman, A. K., Champlin, E., Lintott, A., (eds), The Cambridge Ancient History, Volume 10: The Augustan Empire, 43 BC - AD 69 (1996), p. 434.
- Birley, "Hadrian and the Antonines", in Bowman, A.K., Garnsey. P., The Cambridge Ancient History, Volume 11: The High Empire, AD 70 (2000), P. 139
- Studi in onore di Remo Martini, Vol. 3 (Guffre Editore), 210, p. 470
- "ius Latii" from Smith's Dictionary of Greek and Roman Antiquities, 1875.
- "jus Latii" from Encyclopædia Britannica, 2007
- "Latin Revolt"
- Livy XLIII. 3-4. cf. Galsterer 1971, 8-9: (G 15); Humbert 1976, 225-34: (H 138).
- Bowman, A. K., Champlin, E., Lintott, A., (Eds), The Cambridge Ancient History,Volume 10: The Augustan Empire, 43 BC-AD 69, Cambridge University Press, 2nd Edition, 1996; ISBN 978-0521264303
- Bowman, A. K., Garnsey, P., Rathbone, D., (Eds), The Cambridge Ancient History Volume XI: The High Empire A.D. 70-192, Cambridge University Press, 2nd Edition, 2000, 364-365; ISBN 978-0521263351
- S. A. et al (Eds.), The Cambridge Ancient History Volume VII: The Hellenistic Monarchies and the Rise of Rome, Cambridge University Press; 5th edition 1928, pp 269–271; ISBN 978-0521044899
- Lewis, N., Reinhold, M Roman Civilization: Selected Readings, Vol. 1: The Republic and the Augustan Age, 3rd Edition, Columbia University Press, 1990; ISBN 978-0231071314
- Lewis, N., Reinhold, M Roman Civilization: Selected Readings, Vol. 2: The Empire, 3rd Edition, Columbia University Press, 1990; ISBN 978-0231071338