Henry Mainwaring Henry Mainwaring Sir Henry Mainwaring (1587–1653), was an English lawyer, soldier, author, seaman and politician who sat in the House of Commons from 1621 to 1622. He was for a time a pirate based in Newfoundland and then a naval officer with the Royal Navy. He supported the Royalist cause in the English Civil War. Mainwaring was born in Ightfield, Shropshire, second son of Sir George Mainwaring and his wife Ann, the daughter of Sir William More of Loseley Park in Surrey. His maternal grandfather was Sir William More, Vice-Admiral of Sussex. He graduated from Brasenose College at Oxford University,
Sam Mainwaring life. Mainwaring was raised by his family as a Unitarian. He developed into a quiet yet persuasive public speaker and a tireless worker for activities which he believed important. Mainwaring was a member of the Amalgamated Engineering Union. Late in the 1870s, Mainwaring joined the East London Labour Emancipation League and was an early member of the Social Democratic Federation. However, this group proved to be a disappointment, failing to garner support of an appreciable section of the working class and was believed by many members to overly dominated by the intellectual pretensions and nationalist political views of its patriarch