Background
Rendlesham was the son of Frederick Thellusson, 4th Baron Rendlesham, and his wife Elizabeth Charlotte, daughter of Sir George Prescott, 2nd Baronet, and former wife of General Sir James Duff.
Rendlesham was the son of Frederick Thellusson, 4th Baron Rendlesham, and his wife Elizabeth Charlotte, daughter of Sir George Prescott, 2nd Baronet, and former wife of General Sir James Duff.
His mother died when he was less than one year old. In 1852, aged twelve, he succeeded in the barony on the death of his father. However, as this was an Irish peerage it did not entitle him to a seat in the House of Lords.
Lord Rendlesham married Lady Egidia, daughter of Archibald Montgomerie, 13th Earl of Eglinton, in 1861.
Lady Rendlesham died in January 1880. Lord Rendlesham remained a widower until his death in November 1911, aged 71.
21st United Kingdom Parliament. 22nd United Kingdom Parliament]
He was appointed Sheriff of Suffolk in 1870 and elected to the House of Commons as Member of Parliament (Member of Parliament) for Suffolk East at a by-election in March 1874, a seat he held until the constituency was abolished at the 1885 general election.