After a short career as an army officer, he sat in the House of Commons for two periods, separated by 26 years, and opposed parliamentary reform on both occasions.
After graduating with a Bachelor of Arts degree in March 1828,[3] he was commissioned in April 1828 as a second lieutenant in the Duke of York's rifle corps.
[1] The novelist Emily Eden described him in a letter at that time as "totally unlike all the Thynnes I ever saw—full of fun and dashes out everything that comes into his head".
[6] At the 1831 general election his father bought him a seat as Member of Parliament (MP) for the rotten borough of Weobley, alongside his brother Lord Henry Frederick Thynne.
His wife was estranged from him, and he was repeatedly sued by his creditor Thomas Slingsby Duncombe;[1] in response he canvassed against Dubscombe at the Finsbury by-election in 1834, and at the following year's general election.
[11] When Thynne was discharged from insolvency at the end of that month, the court was told that his debts were £221,059 (equivalent to £26.8 million in 2025[8]), which The Spectator described as an "enormous sum".
[15] Thynne was a skilled marksman who in 1851 shot a golden eagle with a rifle at a hundred yards range, while deer stalking in Scotland as a guest of the Earl of Malmesbury.
[19] Some time in 1872, Thynne called at the London home of the 5th Marquess Townshend, and eloped to France with his wife Clementina (née Duff).
Thynne acknowledged having eloped with Lady Townshend in 1872, but noted that the Marquis had never sued for divorce, and alleged that Lord Macduff had attacked him over the same matter while he was abroad.
Townshend denounced the court, while Vanity Fair reported unnamed others as saying "the only regret is that he [Thynne] was not thrashed earlier and worse".