Leslie, Sir John (1822–1916), 1st baronet, painter and politician, was born 16 December 1822 at Glaslough, Co. Monaghan, the second son in a family of three boys and four girls born to Colonel Charles Powell Leslie MP (d. 1831), and his second wife, Christina, daughter of George Fosberry of Clorane, Co. Limerick. He was educated at Harrow, and graduated BA from Christ Church, Oxford, before taking up a commission in the first life guards. As captain, he won the grand military steeplechase on his own horse. He then embarked on a grand tour in 1847, meeting Rossini, Mrs Browning, George Sand and Mendelssohn.
Inspired by his tour, Leslie resigned his commission in 1850 and pursued artistic ambitions, travelling to Düsseldorf in 1851 to study under K. F. Sohn. His first painting, ‘Children, Christ died for you’, was exhibited at the Royal Academy in 1853 and prompted a letter of praise from Prince Albert. Throughout the 1850s and 1860s he exhibited widely, showing a further twelve paintings at the Royal Academy. He specialised in portraits of titled acquaintances, and had pieces shown at the Grosvenor Gallery, the British Institution and the Paris Salon. In 1862 he exhibited at the Paris Exhibition and in 1872 became an honorary member of the Royal Hibernian Academy. One of a band of pre-Raphaelite enthusiasts that met regularly at Charles Street, London, he was a stalwart member of the artistic set that included Sir John Everett Millais, Ruskin, Rossetti and Watts. He was a close friend of Sir Edwin Landseer and stood by him throughout the controversy that followed the unveiling of his lions at Trafalgar Square. Thackeray and Dickens were also numbered among the many guests at his London home.
On the death of his elder brother, Charles, he succeeded to the vast Monaghan estate in 1871 and began to build and perfect Glaslough House, his replacement for Castle Leslie. He contested the Monaghan seat for the conservatives in a by-election in 1871, defeating the home rule candidate Isaac Butt (qv). Although a reputedly fair landlord (his estate was unusually tranquil during the land war), his speeches in the commons on the evils of land agitation won him the favour of Benjamin Disraeli, who advised the queen to reward him with a baronetcy in 1876. He served as JP, a magistrate, a grand juror and a deputy lieutenant for the counties of Monaghan and Donegal. Staunch in his opposition to home rule, he was defeated in the elections of 1880, 1885 and 1886 by the liberal John Givan, and the nationalists Timothy Healy (qv) and Patrick O'Brien (qv) respectively. He was immersed in the sectarian character of Monaghan politics, stating in 1885 that the only party distinctions in Irish politics were between catholicism and protestantism. He welcomed Orange parades on to his estate at Glaslough in 1905, and the UVF drilled there in 1913–14, under the approving eye of his son, John.
After his parliamentary defeat he painted with renewed vigour, completing a series of frescoes, entitled ‘Christ the healer’, for the chapel of Berkhamsted School, Hertfordshire. In 1904 he showed a portrait of his wife as part of the exhibition by Hugh Lane (qv) of the work of Irish artists at the Guildhall, London. He donated a large oil painting, ‘St Peter denying Christ’, to the Belfast Museum and Art Gallery. It has since disappeared. His pictures, if signed, were marked ‘J. L.’ or with his personal symbol, a small brown dog. Most of his paintings are in private collections. A keen huntsman, fencer and cricketer in his youth, he was a member of the Marylebone Cricket Club from 1841. He was also a member of the Carlton, the Athenaeum and the Travellers’ clubs. In 1906 he retired to England, residing at Manchester Square, London. He died 23 January 1916 at his London home and was interred in the family tomb at Glaslough.
He married on 26 August 1856 Lady Constance Wilhelmina Frances Dawson Damer, youngest daughter of Colonel George Lionel Dawson Damer, and sister of the 4th earl of Portarlington. They had one son John (1857–1944), who succeeded as 2nd baronet after a distinguished military career, retiring as colonel in 1908, and four daughters, Mary, Constance Christina, Theodosia and Olive Louise Blanche. His grandson was the author Shane Leslie (qv).