| Honorific Prefix: | The Right Honourable |
| The Lord Rendlesham | |
| Honorific Suffix: | JP DL |
| Office: | Member of Parliament for Suffolk Eastern |
| Term Start: | 1874 |
| Term End: | 1885 |
| Predecessor: | Frederick Snowdon Corrance Viscount Mahon |
| Alongside: | Viscount Mahon, Frederick St John Barne |
| Successor: | Constituency abolished |
| Birth Name: | Frederick William Brook Thellusson |
| Birth Date: | 9 February 1840 |
| Birth Place: | Florence, Italy |
| Death Place: | Rendlesham Hall |
| Education: | Eton College |
| Alma Mater: | Christ Church, Oxford |
| Parents: | Frederick Thellusson, 4th Baron Rendlesham Elizabeth Prescott Duff |
Frederick William Brook Thellusson, 5th Baron Rendlesham JP DL (9 February 1840 – 9 November 1911), was a British Conservative politician.
Frederick was born in Florence, Italy on 9 February 1840.[1] He was the only son of Frederick Thellusson, 4th Baron Rendlesham, and his wife Elizabeth Charlotte (Prescott) Duff, a 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.
His great-grandfather, the British merchant and banker Peter Thellusson, was perhaps best known for his "extraordinary will" which "gave rise to an act of Parliament known as the Thellusson act."
Thellusson was educated in England at Eton and Christ Church, Oxford. 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.[2]
Lord Rendlesham was appointed Sheriff of Suffolk in 1870 and elected to the House of Commons as member of parliament (MP) for Suffolk East at a by-election in March 1874, a seat he held until the constituency was abolished at the 1885 general election.[3]
Reportedly a fine footballer at Eton and Oxford, he maintained a keen interest in other sports in later life, being on the National Hunt Committee as well as a member of the Jockey Club and the Royal Yacht Squadron.[4]
On 12 February 1887 he was appointed Honorary Colonel of the Suffolk Artillery Militia, and retained the position until the unit was disbanded in 1909.[5]
Failing eyesight in 1911 caused him to resign from long-held positions as chairman of the East Suffolk County Council[6] and the Suffolk Quarter Sessions.[7] He subsequently contracted blood-poisoning, leading to the amputation of his left hand in July 1911.[8] [9]
In 1861, Lord Rendlesham was married to Lady Egidia Montgomerie (–1880) at St Peter's Church, Eaton Square followed by a honeymoon at Peckforton Castle, the seat of John Tollemache.[10] She was a daughter of Archibald Montgomerie, 13th Earl of Eglinton and the former Theresa Howe (née Newcomen) Cockerell (widow of Capt. Richard Howe Cockerell who was an illegitimate daughter of Thomas Gleadowe-Newcomen, 2nd Viscount Newcomen).[11] They had three sons and five daughters, including:
Lady Rendlesham died in January 1880. Lord Rendlesham remained a widower until his death at Rendlesham Hall, near Woodbridge, Suffolk, in November 1911, aged 71.[20] He was succeeded in the barony by his eldest son Frederick.[21]
. F. W. S. Craig . British parliamentary election results 1832–1885 . 1977 . 2nd . 1989 . Parliamentary Research Services . Chichester . 0-900178-26-4 . 462.