The Milvian (or Mulvian) Bridge, usually called the Bridge of Lovers, is located in the northern part of Rome. It is one of the oldest bridges over the Tiber.
According to historians, king Maksentius suffered defeat on that bridge in the battle with the army of Constantine the Great in 312. There is a legend saying that the emperor saw an inscription IHS on a wall just before the battle. The victory is explained by the god's intervention. Since then, Rome has started to implement a pro-Christian policy.
The current bridge is better known for its occurence in the novel "I Want You" by the Italian writer Federic Moccia. The author of the book located on the bridge a scene with a couple hanging padlocks with their names on the railing. As a sign of their everlasting love they threw the keys into the water of the Tiber. There is also a theory saying that the custom was adopted from students of the Florentian school Sanita in Costa San Giorgio who in the beginning of the summer break would take padlocks from their school lockers and hang them on railings of the bridge.
The bridge is filled with love padlocks, even lamps or trash bins have started to bend under the weight. Because of that the city authorities have been trying to restrict the custom. However, those in love still go to the Milvian Bridge to leave their padlocks there. Similar traditions were also started in other Italian or European cities.