Born into a family that had provided MPs for the county since the seventeenth century, Cartwright sat for Northamptonshire South between 1858 and 1868 as a silent, but loyal Conservative.
Cartwright, the tenth child of the long-standing Northamptonshire MP William Ralph Cartwright, was educated at Eton prior to being appointed, at a personal cost of £1,200, to the Grenadier Guards, aged 17, in July 1832.
It came as a surprise to local commentators when Cartwright, ‘shrowded behind a veil of impenetrable mystery’, was announced as the Conservative candidate for the 1858 South Northamptonshire by-election.
Cartwright’s first parliament was his best attended – he voted in 51.4% of divisions (the average was 34.8%). Aside from a rebellious vote in the minority for Spooner’s anti-Maynooth motion, 29 Apr. 1858, he followed the Conservative whip on all major issues, including in support of the second reading of the Derby government’s reform bill, 31 Mar. 1859. He was a silent member throughout his career. Cartwright was returned uncontested in 1859, when he reaffirmed his Conservative principles and endorsed the proposed expansion of the navy to ensure Britain’s security against a much-feared French invasion.
Ahead of the 1865 election, Cartwright’s silence in debate was criticised by the Northampton Mercury, which accused him of possessing ‘no influence in the House’.
For financial reasons, Cartwright had planned to retire in 1868, but was persuaded to offer again by the local Conservative association after Rainald Knightley, the county’s other incumbent Conservative, had refused to stand with the financially independent Colonel Lloyd Lindsey, who had been identified as Cartwright’s replacement.
