The flag of Britain

The flag of Britain, commonly known as the Union Jack (which derives from the use of the Union Flag on the jack-staff of naval vessels), embodies the emblems of three countries under one Sovereign. The emblems that appear on the Union Flag are the crosses of three patron saints: The red cross of St George, for England, on a white ground; The white diagonal cross, or saltire, of St Andrew, for Scotland on a blue ground; The red diagonal cross of St Patrick, for Ireland, on a white ground.