 Although the Grand National was run as normal in 1940 and most other major horse races around the world were able to be held throughout the war, the commandeering of Aintree Racecourse for defence use in 1941 meant no Grand National could be held from 1941 to 1945.During the 1950s the Grand National was dominated by Vincent O'Brien, who trained different winners of the race for three consecutive years between 1953 and 1955.Early Mist secured O'Brien's first victory in 1953; Royal Tan won in 1954, and Quare Times completed the Irish trainer's hat-trick in 1955.