English horse-racing event, run over 2.4 km/1.5 mi at Epsom Downs, Surrey, every June. It was established in 1780 and named after the 12th Earl of Derby. The USA has an equivalent horse race, the Kentucky Derby.
Green and red replaced blue and white as the national colours in 1910. The armillary sphere surrounds the shield of Portugal. Effective date: 30 June 1911.