 In 1766 and 1797 payments are recorded to Bedlam Hospital and John Munro or his son Thomas Munro, the mad-doctors who later attended to George III, and in 1774 an Inquisition of Insanity found that Leigh had been 'a Lunatick of unsound mind' over the previous five years and committed him to the guardianship of his sister, Hon.Mary Leigh, his uncle Reverend John Craven, and his cousin William, Lord Craven at which point he vanished from public view.A prayer written by his sister Mary in about 1775 survives