Bred at Oakley Hall, near Kettering, by General (then Colonel) Mark Pearson, she was a full sister to the triple crown winner Lord Lyon (b c 1863). A dark brown filly she stood 15.3 hands and was said to have had a Stockwell head, very full between the eyes and her ears were curled back at the points, powerful neck, fine shoulders, and an extraordinary depth of girth; but she ran up, like many of the sort, very light and waspish in the barrel. Said to be very light of bone, and on the off-fore retaining the blemish caused by getting her feet over the collar-shank when a yearling, she was overall thought a \"beautiful filly. She ran from 1866 through 1868. As a two year old she won £275 at Newmarket Craven, the £645 Grand Stand Plate at Ascot Spring, the £685 Woodcote Stakes at Epsom beating Hermit (ch c 1864 Newminster), the £457 Triennial and the £760 New Stakes at Ascot in June, the £1900 July Stakes and the £1330 Chesterfield Stakes at Newmarket, the £1050 Lavant Stakes at Goodwood, the £1225 Champagne Stakes at Doncaster in a canter, the £750 Hopeful Stakes at Newmarket First October in a canter, and the £1310 Criterion Stakes at Newmarket Houghton. As a three year old she won the £4150 One Thousand Guineas Stakes at Newmarket First Spring, finished second for the Oaks won by Hippia (b f 1864 King Tom), the £1700 Coronation Stakes at Ascot, the £480 Great Yorkshire Stakes at York, the £5425 Great St Leger and the Cup at Doncaster again beating Hermit in both races. As a four year old she finished second for the Beaufort Cup at Bath and the Triennial at Ascot, the latter won by the Doncaster Cup, Great Ebor Handicap and Liverpool Cup winner Mandrake (ch c 1864 Weatherbit), and third for the Cup at Stockbridge. She entered the Pearson stud where she produced two dead foals, the second by the Derby winner Beadsman (br c 1855 Weatherbit), in 1870 and 1871. In 1872 Achievement produced an unnamed bay colt by the triple crown winner Gladiateur (b c 1862 Monarque) but died the same year.