A pretty difficult construction
The first mention dates back to 1180. 3 years later, a Pontiff brother, Etienne, launched the "trade" of the bridge. He also raised the hospital and a small chapel...
Our wooden bridge collapsed in 1190, because of kings Richard Lionheart and Philip Augustus' troops, who crossed it one day, were too heavy! All the soldiers died, of course...
Popes, bishops and archbishops gave for the reconstruction, which took a loooong time. Even king Richard, witness of the accident, allowed monks to collect money! Meanwhile, people had to cross the river with a boat!
Then, in 1309, Pontiff brothers gave the bridge and the hospital to the abbey of Hautecombe, because they had no money to manage the place. But they couldn’t afford the construction, too! They said it was "an endless work"... So in 1334, they gave it to city mayors.
But at that time, only 2 arches were built... until king Charles V of France founded a toll on the bridge, so this money was used for the building site... finally, in 1407, we raised half the bridge!
A desperate situation!
But a big flood of river Rhône (300 houses were destroyed) damaged an arch, the same year. Oh my god, they had to rebuilt, one more time... Desperate, the city mayors wrote to the king, to the most powerful lords, to the Pope himself in order to find money!
In 1410, Charles VI the Mad finally helped them. Well, for centuries, floods and storms damaged the bridge. Each time, they rebuilt it... especially in the 17th and 18th century: we had 20 arches at that time.
From the Middle-Ages to modern times
Since the Middle-Ages, our bridge was protected by the redoute de la Sentinelle
("Sentry redoubt"), a kind of square tower with a drawbridge, located on the 7th arch. At the end of the bridge, we had a kind of bastion flanked by towers with a small chapel dedicated to the Holy Spirit.
They destroyed the chapel in 1773, the bastion and the tower in 1793 during the city siege... The current bridge dates back to 1953: the old one was destroyed by German army in 1944...