Has a filly ever won the Derby?

Of the five ‘Classic’ races run in Britain – namely, the 2,000 Guineas, 1,000 Guineas, Derby, Oaks and St. Leger – the 1,000 Guineas and the Oaks are restricted to three-year-old thoroughbred fillies, but the other three are open to three-year-old thoroughbred colts and fillies. Nowadays, the Derby is rarely contested by fillies; the last filly to run in the race was Cape Verdi, trained by Saeed bin Suroor, who started favourite after winning the 1,000 Guineas in 1998, but could finish only ninth of the 15 runners. Nevertheless, since the Derby was inaugurated in 1780, a total of six fillies have won; the most recent of them was Fifinella who, in 1916, won a ‘substitute’ Derby run at Newmarket and, just for good measure, won the so-called ‘New Oaks’, over the same course and distance, two days later.