<P> The Derby originated at a celebration following the first running of the Oaks Stakes in 1779 . A new race was planned, and it was decided that it should be named after either the host of the party, the 12th Earl of Derby, or one of his guests, Sir Charles Bunbury (the Bunbury Cup run at Newmarket would later be named in his honour). According to legend the decision was made by the toss of a coin, but it is probable that Bunbury, the Steward of the Jockey Club, deferred to his host . The inaugural running of the Derby was held on Thursday 4 May 1780 . It was won by Diomed, a colt owned by Sir Charles Bunbury, who collected prize money of £ 1,065 15s . The first four runnings were contested over 1 mile, but this was amended to the current distance of 11⁄2 miles in 1784 . Lord Derby achieved his first success in the event in 1787, with a horse called Sir Peter Teazle . </P> <P> The starting point of the race was moved twice during the 19th century . The first move, suggested by Lord George Bentinck, was in 1848, and the second was in 1872 . It was discovered in 1991 that the exact length of the race was one mile, four furlongs and 10 yards . </P> <P> Initially, the Derby was run on a Thursday in late May or early June, depending on when Easter occurred . In 1838 the race was moved to a Wednesday to fit in with the railways' timetables, but still followed the moveable feast of Easter . In the 20th century, the race was run on the first Wednesday in June from 1900 until 1995, not including 1915 to 1918 (during the First World War), when it was on a Tuesday . During the Second World War, from 1942 until 1945 the race was run on a Saturday, as it was in the post-war years of 1947 to 1950 and again in 1953 . In 1995 the day was changed from the first Wednesday in June to the first Saturday, and since then all the races have taken place on that day . </P> <P> The Derby has been run at Epsom in all years except during the world wars . From 1915 to 1918 and from 1940 to 1945, the Derby was run at Newmarket . These races are known as the' New Derby' . </P>

When was the derby last run on a wednesday