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,
William Mainwaring men did not go in to work. Mainwaring did get the South Wales nomination for the secretaryship of the Miners' Federation of Great Britain in 1932, after the death of A. J. Cook. A preferential voting system was used, and Mainwaring came in third place on first preference votes, being eliminated from the voting. The death of Lieutenant-Colonel David Watts-Morgan, the Labour Member of Parliament (MP) for Rhondda East, in early 1933 left a vacancy for a Labour candidate in which the influence of the miners was predominant. Mainwaring's name was immediately mentioned as a possible candidate, with rivals including