The Senones, who settled on the banks of the river Yonne and founded the city of Agenticum, which we know to-day as Sens, were one of the most influential people in Gaul--even the Parisii were considered of less account--and did not submit to the Roman yoke until the final defeat of Vercingetorix. The change of dominion, however, in no way detracted from the importance of their capital city, but rather enhanced it, since the conquerors made the town metropolis of the fourth Lugdunensis, and were at some pains to rebuild it in a fashion befitting its position. Six great highways met within its walls; arches, aqueducts and amphitheatres sprang up all over the city, and Agenticum henceforth became a prosperous and powerful stronghold, well able to withstand the incursions of later days, of which there were many, on the part of the Franks and the Saracens and, finally, of the Normans. Christianity was introduced by the martyr-saints Savinian and Potentian, who, as at Chartres, built the first church in the city, thus laying, so tradition has it, the foundations of the Cathedral which was to come in after times. The town then became an archbishopric, and later, like most towns of any standing, a hereditary countship, the proximity of the two overlords, spiritual and temporal, leading not infrequently to disastrous results, especially when in the twelfth century a communal power sprang up and contributed a third factor to the contest. In 1234 Louis IX. married Marguerite de Provence in the Cathedral of Saint Etienne, and on his return from the Holy Land, five years later, with the precious relics purchased from the Emperor of Constantinople, the reliquary and its contents were paraded through the streets in a palanquin, borne by the king and his brother, Robert d’Artois, who walked bare-headed and bare-footed at the head of the procession, casting aside all their royal state--which, indeed, poor Louis would have gladly left for ever--to set an example of reverent homage to the people of Sens. Thomas à Becket lived for some months in the Abbey of Sainte-Colombe by the river-side, founded by one of the Chlothars in the seventh century in memory of the young virgin saint who suffered martyrdom under the rule of Aurelian.