William Mainwaring (English politician) Burdett. Mainwaring had previously resisted Burdett's calls for an inquiry into prison abuses, particularly at Coldbath Fields Prison. Mainwaring was defeated by Burdett but the election was declared void in 1804 and in the following contest William's son George Boulton Mainwaring was elected. The result was reversed in favour of Burdett in 1805 and the back in favour of Mainwaring Junior in 1806. Mainwaring did not contest the 1807 election and Burdett was not elected. He died in 1821, leaving one son. William Mainwaring (English politician) William Mainwaring (6 Oct 1735 – 28 February 1821) was the MP for Middlesex
William Massey-Mainwaring who lent items from his collection to public galleries around the country. He was involved in Conservative politics and in 1892 put his name forward as a candidate for the Hackney Central constituency. Eventually he stood aside in favour of Sir Andrew Scoble. In 1895 he was elected as member of parliament for Finsbury Central, holding the seat until 1906. He died suddenly from influenza and diabetes at his London home in March 1907, aged 61. William Massey-Mainwaring The Honourable William Frederick Barton Massey-Mainwaring (28 May 1845 – 12 March 1907) was an Irish art collector and Conservative Party politician