Mantes' official name is Mantes-la-Jolie, meaning 'Mantes the pretty', and pretty it certainly is. The town grew initially as a staging post, being situated about halfway between Paris and Rouen - the centres of power for France and Normandy. Some of the town's important buildings from this time have survived to the present day.
Perhaps the most famous moment in Mantes' history came in 1593, when King Henri IV converted to Catholicism in the town with the comment, "Paris is worth going to mass for". Mantes' Gothic Notre Dame collegiate church then took on a significant importance. Based on the Parisian cathedral of the same name, the church boasts original stained-glass windows dating back to the 12th century - it's well worth a visit for these alone.