The Prix du Jockey Club, the French Derby, was first run at Chantilly in 1836 over 2500 metres when won by Franck, owned by Lord Seymour, trained by Thomas Carter and ridden by Tom Robinson. For over a century it was restricted to horses born and bred in France, and that did not change until 1948. In 1843 it was reduced to 2400 metres, and in 1848 it had to be run at Versailles because of the Revolution, but had to be cancelled altogether in 1871 due to the ongoing Franco-Prussian War. There have been 5 dead-heats to date, three of which were not subject to a run-off, the first in 1882 between Dandin and Saint James, in 1886 Sycomore and Upas shared the spoils, and again in 1908 when Sea Sick and Quintette could not be separated. However, two further dead-heats occured when the pairs of owners opted for a run off. In 1843 Renounce got the better of Prospero, while in 1856 Lion saw off Diamant second time around. During the First World War the race was abandoned in 1915, while between 1916 and 1918 a substitute 'Prix de Trois Ans' was staged, in 1916 at Moulins in October when Teddy won, in 1917 back at Chantilly when Brumelli won, and in 1918 at Maisons-Laffitte when Montmartin was victorious. In both 1919 and 1920 the race was held at Longchamp, won by Tchad and Soubier respectively. During the Second World War the 1940 race, called the Prix de Chantilly, was actually held at Auteuil over 2600 metres when the appropriately named Quicko won. In the War years 1941 and 1942 the race was staged at Longchamp, with La Pacha and Magister winning, while in 1943 and 1944 the race was reduced to 2300 metres when held at Le Tremblay. Between 1945 and 1948 the race was held at Longchamp, the 1948 running, won by Bey, being particularly important as it was open to non-French horses for the first ime, although it was to be a further 34 years before Assert became the first foreign trained winner, it being trained by David O'Brien in Ireland. It was not until 2005 that the race was shortened to its current distance of 2100 metres. The race is viewed as an important guide to future Arc winners and, to date (2024), eleven winners have gone on to win the Prix de L'Arc de Triomphe, the first being Ksar in 1921.