What is "rockfel"

Rockfel (1935–November 1941) was a British Thoroughbred racehorse and broodmare, best known for winning two Classics in 1938. In a career which lasted from July 1937 until May 1939 she ran thirteen times and won eight races. Rockfel began her career at the lowest level, being beaten in a selling race, but improved to become recognised as one of the best British racemares of the 20th century. In 1938 she was the dominant three-year-old in England, winning the 1000 Guineas over one mile at Newmarket and the Oaks over one and a half miles at Epsom. In the autumn she defeated colts in the Champion Stakes and the Aintree Derby and was retired after winning her only race as a four-year-old. She produced one foal before dying in November 1941.