The belfry was the symbol of the city power in the Middle-Ages! Rouen's belfry, this "Big Clock" (Gros Horloge in French) wasn't an exception.
We found here a primitive belfry, called tour Massacre ("Slaughter tower"), which used to house bells called Ribaud and Rouvel. In 1382, king Charles VI the Mad decided to punish inhabitants because they rebelled: he razed the tower and removed the bells... so there!
In 1389, Rouen city owned the bells and re-raised the current belfry. The current clock was erected on a Renaissance arch (dating back to 1527).