Henry Mainwaring in the King's cause in the English Civil War, was exiled to France, and died in poverty. He was buried at St. Giles' Church, Camberwell, London, on 15 May 1653. Mainwaring married a daughter of Sir Thomas Gardiner in 1630. She died in 1633. His brothers were Sir Arthur Mainwaring, Carver to Prince Henry, George Mainwaring, the defender of Tong Castle, and Sir Thomas Mainwaring, the Recorder of Reading. The Mainwaring family was old and distinguished, probably having arrived in England in the train of William the Conqueror (1066). Henry Mainwaring Sir Henry Mainwaring (1587–1653), was an English lawyer, soldier,
Captain Mainwaring clerk, chief clerk and eventually manager), Mainwaring reveals in the same episode that he considers it a mere "tinpot branch" and his career is at a seemingly permanent standstill, as revealed in A. Wilson (Manager)?: whenever he applies for promotions he is always turned down due to his unimpressive background. Mainwaring's pomposity and snobbery work against him, as he is frequently dependent on those in the Home Guard that he considers beneath him, such as Sergeant Wilson, his chief clerk at the bank with whom he shares an antagonistic friendship and Private Walker, a black-marketeer who interrupts during Mainwaring's lectures