This success was achieved despite wartime restrictions which saw the closure of Longchamp as well as strict limits imposed both on travel and on the amount of grain used for the horses ' feed .
Longchamp is france 's most important racecourse .
This success was achieved despite wartime restrictions which saw the closure of Longchamp , France 's most important racecourse , as well as strict limits imposed both on travel and on the amount of grain used for the horses ' feed .