SEQUANI, in ancient geography, a Celtic people who occupied the upper basin of the Arar (Saône), their territory corresponding to Franche-Comté and part of Burgundy. Before the arrival of Caesar in Gaul, the Sequani had taken the part of the Arverni against their rivals the Aedui and hired the Germans under Ariovistus to cross the Rhine and help them (71 B.C.). But although his assistance enabled them to defeat the Aedui, the Sequani were worse off than before, for Ariovistus deprived them of a third of their territory and threatened to take another third. The Sequani then appealed to Caesar, who drove back the Germans (58), but at the same time obliged the Sequani to surrender all that they had gained from the Aedui. This so exasperated the Sequani that they joined in the revolt of Vercingetorix (52) and shared in the defeat at Alesia. Under Augustus, the district known as Sequania formed part of Belgica. After the death of Vitellius, the inhabitants refused to join the Gallic revolt against Rome instigated by Julius Civilis and Julius Sabinus, and drove back Sabinus, who had invaded their territory. A triumphal arch at Vesontio (Besançon), which in return for this service was made a colony, possibly commemorates this victory. Diocletian added Helvetia, and part of Germania Superior to Sequania, which was now called Provincia maxima Sequanorum, Vesontio receiving the title of Metropolis civitas Vesontiensium. Fifty years later Gaul was overrun by the barbarians, and Vesontio sacked (355). Under Julian it recovered some of its importance as a fortified town, and was able to withstand the attacks of the Vandals. Later, when Rome was no longer able to afford protection to the inhabitants of Gaul, the Sequani became merged in the newly formed kingdom of Burgundy.
See T. R. Holmes, Caesar’s Conquest of Gaul (1899), p. 483; A. Holder, Altceltischer Sprachschatz, ii. (1904); Mommsen, Hist. of Rome (Eng. trans.), bk. v. ch. vii.; Dunod de Charnage, Hist. des Séquanois (1735); J. D. Schöpflin, Alsatia illustrata, i. (1751; French trans. by L. W. Ravenèz, 1849).