In Gallic times the city was important as a crossing point of the Loire. Becoming part of the Roman Empire during the 1st century AD, the city was named “Caesarodunum” (“hill of Caesar”). The name evolved in the 4th century when the original Gallic name, Turones, became first “Civitas Turonum” then “Tours”. It was at this time that the amphitheatre of Tours, one of the five largest in the Empire, was built. Tours became the metropolis of the Roman province of Lugdunum towards 380–388, dominating the Loire Valley, Maine and Brittany. One of the outstanding figures of the history of the city was Saint Martin, second bishop who shared his coat with a naked beggar in Amiens. This incident and the importance of Martin in the medieval Christian West made Tours, and its position on the route of pilgrimage to Santiago de Compostela, a major centre during the Middle Ages.