Greer, Sir (Joseph) Henry (1855–1934), horse breeder, was born 9 February 1855 at Grange, Moy, Co. Tyrone, eldest son of Lt.-gen. Henry Harpur Greer, CB, and Agnes Isabella Greer (née Knox). Educated at Wellington and the Royal Military College, he then joined the 74th Regiment of Foot (Highland Light Infantry) in 1874. He served most of his time in India, where his interest in horses began; when not racing them he played a lot of polo and was for some time honorary secretary of the Umbella Polo Club. He retired from his regiment a few years before the first Boer war (1880–81), but rejoined when the war broke out. In 1890 he finally retired at the rank of captain.
In 1888 he set up his own stud, Brownstown in Tully, Co. Kildare, and began breeding horses; he later sold the stud to the Aga Khan. His first great success was with Tragedy who in the following year won the Irish Derby and the Cork Derby. His colours (white with tartan sleeves and a red cap) were first recorded in 1889. In 1892 he set up a very successful partnership with Sam Darling, whereby he bred the horses and Darling trained them. Outside this partnership his most notable purchase was Gallinule, who became a champion sire of successful horses such as Wildflower, Nighthawk, and Pretty Polly. He also spent some time developing the Aga Khan's stud near Sheshoon, Co. Kildare.
In 1901 he was elected to membership of the Jockey Club; he was senior steward in 1908–10 and again in 1914. On his second appointment as steward he dissolved his partnership with Sam Darling. He excelled in the business of running a stud; this was recognised in 1915 when he was appointed director of the newly founded National Stud in Co. Kildare, where he remained until his resignation in 1933, due to illness. The greatest sire bred at the National Stud during his time as director was Blandford, who amassed a record total of prizewinning in Britain and Ireland. In 1925 Greer was knighted for his services to bloodstock breeding. He was a member of the Free State senate (1922–9). A modest, quiet man, Greer was a very popular figure within racing circles – he was a member and a steward for some time of the Irish Turf Club – and well respected in Ireland. He also enjoyed shooting, fishing, and golf. He died 25 August 1934 in Kildare.
He married (1886) Olivia Mary, daughter of Maj.-gen. George de la Poer Beresford. They lived at the Curragh Grange, Newbridge, Co. Kildare. Their two sons, Eric Beresford Greer and Francis St Leger Greer, both joined the Irish Guards and were killed on the Western Front in July and February 1917 respectively.