He had Strawberry Hill House built in Twickenham, south-west London, reviving the Gothic style some decades before his Victorian successors. His literary reputation rests on the first Gothic novel, The Castle of Otranto (1764), and his Letters, which are of significant social and political interest. They have been published by Yale University Press in 48 volumes.
He was the son of the first British Prime Minister, Sir Robert Walpole. As Horace Walpole was childless, on his death his barony of Walpole descended to his cousin of the same surname, who was created the new Earl of Orford.
Walpole was born in London, the youngest son of British Prime Minister Sir Robert Walpole and his wife Catherine. Like his father, he received early education in Bexley; he was also educated at Eton College and King's College, Cambridge.
Walpole's first friends were probably his cousins Francis and Henry Conway, to whom Walpole became strongly attached, especially Henry.:34 At Eton he formed with Charles Lyttelton and George Montagu the "Triumvirate", a schoolboy confederacy. More important were another group of friends dubbed the "Quadruple Alliance": Walpole, Thomas Gray, Richard West and Thomas Ashton.:35
At Cambridge Walpole came under the influence of Conyers Middleton, an unorthodox theologian. Walpole came to accept the sceptical nature of Middleton's attitude to some essential Christian doctrines for the rest of his life, including a hatred of superstition and bigotry.:48 Walpole ceased to reside at Cambridge at the end of 1738 and left without taking a degree.:49
In 1737 Walpole's mother died. According to one biographer his love for his mother "was the most powerful emotion of his entire life...the whole of his psychological history was dominated by it".:44 Walpole did not have any serious relationships with women; he has been called "a natural celibate".:47 Walpole's sexual orientation has been the subject of speculation. He never married, engaging in a succession of unconsummated flirtations with unmarriageable women, and counted among his close friends a number of women such as Anne Seymour Damer and Mary Berry named by a number of sources as lesbian. Many contemporaries described him as effeminate (one political opponent called him "a hermaphrodite horse"). Biographers such as Timothy Mowl explore his possible homosexuality, including a passionate but ultimately unhappy love affair with the 9th Earl of Lincoln. Some previous biographers such as Lewis, Fothergill, and Robert Wyndham Ketton-Cremer, however, have interpreted Walpole as asexual.