Bred by George Stanhope (1805-1866), 6th Earl of Chesterfield, who also bred the Oaks winners Industry (br f 1835 Priam) and Lady Evelyn (b f 1846 Don John), Crucifix was purchased and raced by Lord George Bentinck (1802-1848), third son of the 4th Duke of Portland, who bred the One Thousand Guineas winners Firebrand (ch f 1839 Lamplighter) and The Flea (b f 1846 Coronation). Her dam Octaviana (b f 1815), daughter of the St Leger winner Octavian (ch c 1807 Stripling), also produced the July Stakes winner Crusader (br c 1823 Cervantes).

Her conformation was thought to deviate considerably from the ideal. Standing nearly 16 hands she was described as having a very straight, lean head with good eyes, long ears and open nostrils. Her neck was long and light, her shoulders thin and oblique and her brisket deep, however, her chest was narrow and her arms and legs small and her toes alleged to turn out like those of a ballerina. With flat sides and thighs, short back ribs and drooping quarters, her overall appearance was called "wiry". Nevertheless she was as "nimble as a cat, and had the useful faculty of reaching the top of her speed in a few strides, and without any apparent effort". Undefeated, she ran only as a two and three year old, winning all her races so easily that she was said to be "altogether one of the most extraordinary animals on record". Among her victories were the One and Two Thousand Guineas Stakes and the Oaks Stakes, after which "her legs quite gave way".

She was later owned by the Hon Edward Lloyd Mostyn, who bred the Oaks And St Leger winner Queen of Trumps (br f 1832 Velocipede) and Henry Agar-Ellis Clifden (1825-1866), 3rd Viscount Clifden. In the stud she got the Derby and St Leger winner Surplice (b c 1845 Touchstone), the Royal Hunt Cup winner Chalice (b f 1852 Orlando) and the stallion Cowl (b c 1842 Bay Middleton). The taproot mare of Family 2-i, her descendants include the One Thousand Guineas, Oaks and St Leger winner Meld (b f 1952 Alycidon), the One Thousand Guineas winner Musical Bliss (b f 1986 The Minstrel), the Oaks winner Placida (br f 1874 Lord Lyon), the Oaks winner Shahtoush (b f 1995 Alzao), the Oaks winner Ramruma (ch f 1996 Diesis), the Prix du Jockey Club winner Ajax (b c 1901 Flying Fox), the Ascot Gold Cup winner Precipitation (ch c 1933 Hurry On), the Coronation Cup winner Persian Gulf (b c 1940 Bahram) and the Derby winner Charlottown (b c 1963 Charlottesville).

Crucifix died in 1858 and was buried beside Bay Middleton (b c 1833 Sultan) at Danebury, near Stockbridge, Hampshire. John and Alfred Day were said to have "each planted a cedar tree" near their graves.