Overview
The Hon. Seton Montolieu Montgomerie (15 May 1846 – 26 November 1883) was the second son of Archibald Montgomerie, 13th Earl of Eglinton (1812–1861).
Life and family
He was born at the Clarendon Hotel, London. Seton may have been so named following his father being created Earl of Winton, a title previously held by the Seton family. His mother, Theresa Newcomen, born in Calcutta, was an illegitimate daughter of Thomas Gleadowe-Newcomen, 2nd Viscount Newcomen. Lady Theresa died in December 1853 and Seton's father remarried in 1858, his new wife being Lady Adela Caroline Harriet Capell (1828–1860), daughter of Arthur Capell, 6th Earl of Essex. Seton had two half-sisters through this marriage:
Lady Sybil Amelia Montgomerie (died 3 February 1932)
Lady Hilda Rose Montgomerie (died 18 June 1928)
Seton's older sister, Lady Egida Montgomerie (died 13 January 1880), married Frederick William Brook Thellusson, 5th Baron Rendlesham. His older brother was Archibald Montgomerie, who became the 14th Earl of Eglinton (3 December 1841 – 30 August 1892).
From Wikipedia (CC BY-SA 4.0).