Wikipedia
Paris–Brest–Paris (PBP) is a long-distance cycling event. It was originally a 1200km bicycle race from Paris to Brest and back to Paris. The start of the ride is scheduled from the national velodrome situated in Saint-Quentin-en-Yvelines. It is one of the oldest bicycling events still regularly run (the oldest being the Catford CC Hill Climb ). The last time it was run as a race was 1951. The most recent edition of PBP ran from 16 August to 20 August 2015.
In 1931 amateur cyclists were separated from professionals. There are two independent long distance bicycle tours. One is the brevet (also called randonnée), in which cyclists ride individually. The goal is to make it within 90 hours, but with no competition. This is held every four years. The other is an audax where cyclists ride in a group, held every five years. So in 1931 there were three independent cycling events, sharing the same route.
The audax is organised by the Union des Audax Françaises, while the brevet is organised by the Audax Club Parisien.