The bridge had great strategic importance. When it was built, it was the only fixed river crossing between Lyon and the Mediterranean Sea. It was also the only river crossing between the Comtat Venaissin (an enclave controlled by the Pope) and France controlled by the kings of France. As such, it was closely guarded on both sides of the river. The right bank was controlled by the French crown. The fortress of the Tour Philippe-le-Bel was close enough to see the bridge. This was built at the beginning of the 14th century. On the Avignon side, a large gatehouse was built in the 14th century. It was changed a lot in the 15th century. The walkway passed over the city wall and down a ramp (now destroyed). This led into the city.