The truth!
First race was on the 26th May 1923, 33 cars, race started at 4pm. Fastest lap Bentley 9 min 39 secs, circuit length 10.6 miles avg speed 66.6mph.
Race came about as a result of Charles Faroux and Gearges Durand collaborating on the idea of a 24 hour race, Durand was already running GP's at the time.
The race carried on every year until 1939 and then resumed again in 1949 and I'm not aware of any breaks since then.
Hope that helps.
Jem