Sequana is the name given by Julius Caesar in De Bello Gallico (Book I, 1) to the River Seine, which rises at the Sources-de-la-Seine, on the plateau of Langres, about thirty kilometres to the north-west of Dijon (Côte d’Or), and flows in the Paris Basin and on into the English Channel, near Le Havre (Seine-Maritime).1785 With the River Marne (Matrona), it marked the frontier between the Belgae and the Gauls:‘ Gallia est omnis divisainpartestres, quarum unam incoluntBelgae, aliam Aquitani, tertiam qui ipsorum linguaCeltae, nostraGalliappellantur. Hi omnes lingua, institutis, legibus inter se differunt. Gallos ab Aquitanis Garumna flumen, a Belgis Matrona et Sequanadividit.
Four campaigns of excavations, carried out at the Sources-de-la-Seine, revealed the existence of a huge Gallo-Roman water sanctuary, notably composed of a temple, rooms and baths, nine inscriptions to the Dea Sequana, a bronze statue representing the goddess standing on a boat with a duck-headed prow, a stone statue of a seated goddess and a considerable amount of votive offerings: 391 ex-votos in stone, 256 in metal and 278 in wood.1786 Some of the votive offerings are images of the pilgrims themselves, while others are representations of body parts, such as legs, hands, breasts, pelvises, etc. These discoveries revealed that Sequana was the eponymous goddess of the River Seine and that her cult was prominent in Gallo-Roman times.
The name was given erroneously by Strabo as Epkoanas (1st c. BC) and by Ptolemy as Σηχοανα (2nd c. AD). It had evolved into Segona and Sigona by the 6th c. AD and Secana in 844, see Nègre, 1990, p. 43, n°1066.
Deyts, Un Peuple de Pèlerins, p. 5.