Joseph Severn was born at Hoxton on the 7th of December 1793, his father, a musician, coming of an old Gloucestershire family. Severn was one of seven children; two of his brothers, Thomas (1801–1881) and Charles (1806–1894), became professional musicians, and Severn himself was an adroit pianist.
He was apprenticed at the age of 14 to William Bond, an engraver.
In 1815, he was admitted to the Royal Academy Schools in London and exhibited his first work in oil, Hermia and Helena, a subject from A Midsummer Night's Dream, along with a portrait miniature, "J. Keats, Esq", in the Royal Academy Exhibition of 1819.
He was an intimate friend of Keats the poet, whom he accompanied to Italy in 1820 and nursed till his death in 1821. His picture of "The Death of Alcibiades " then obtained for him an Academy travelling studentship, and he returned to Rome, where he lived till 1841, marrying in 1828 the daughter of Lord Montgomerie, a ward of Lady Westmoreland, one of his chief patrons, and mingling in the congenial art circles of the city. In 1861, after living in England for nineteen years, mainly for the education of his children, he was appointed British consul at Rome, a post which he held till 1872, and during a great part of the time he also acted as Italian consul. His most remarkable work is the "Spectre Ship" from the Ancient Mariner. He painted "Cordelia watching by the Bed of Lear, " the "Roman Beggar, " "Ariel, " "The Fountain, " and "Rienzi, " executed a large altar-piece for the church of St Paul at Rome, and produced many portraits, including one of Baron Bunsen and several of Keats. He died at Rome on the 3rd of August 1879.
In 1818, Severn was awarded the gold medal of the Royal Academy for his painting Una and the Red Cross Knight in the Cave of Despair which was inspired by the epic poem The Faerie Queene by Edmund Spenser. It was the first time the prize had been awarded in eight years and the painting was exhibited at the Academy in 1820. This award also allowed Severn to apply for a three years' traveling studentship, paid for by the Royal Academy.
In 1892 the first significant collection of Severn's papers was published by William Sharp in The Life and Letters of Joseph Severn. Modern critics have cast doubt on the accuracy of Sharp's transcriptions and noted important omissions and embellishments.
In 1965, Sheila Birkenhead published Illustrious Friends: The story of Joseph Severn and his son Arthur.
In 2005, Grant F. Scott published Joseph Severn: Letters and Memoirs in which he re-edited the original material, added hundreds of newly discovered letters, included numerous reproductions of Severn's paintings, and prefaced this material with a critical introduction and commentary.
In 2009, Sue Brown published the biography Joseph Severn, A Life: The Rewards of Friendship using Scott's new information to provide a reassessment of Severn's character, his friendship with Keats, and his own subsequent artistic and diplomatic career.
In 1828 Severn married Elizabeth Montgomerie, the natural (i. e. illegitimate) daughter of Archibald, Lord Montgomerie (1773–1814) and the ward of Lady Westmoreland, one of the artist's patrons in Rome. Together they had six children, three of whom became noteworthy artists: Walter and Arthur Severn, and Ann Mary Newton, who married the archeologist and Keeper of Antiquities at the British Museum, Charles Thomas Newton. Mary had a successful painting career in England, supporting the family for a time and executing a number of portraits of the Royal Family. Her early death from measles at the age of 32 affected Severn. In 1871, Arthur Severn married Joan Ruskin Agnew, a cousin of the Victorian art and social critic John Ruskin. The Severns had another child, Arthur, who died as an infant in a crib accident.
According to a new edition of Severn's letters and memoirs, Severn fathered an illegitimate child named Henry (b. 31 Aug 1819) about a year before leaving England for Italy. In 1826 there were plans for father and son to reunite, but Henry died, aged 11, before he could make the journey to Rome
