He was born the eldest son of Sir John Danvers of Dauntsey, Wiltshire and Elizabeth, fourth daughter and coheiress of John Neville, Baron Latimer.
The family which took its name from the manor of Dauntsey is said by Macnamara, op.cit, originally to have been called "Oldstock", which he deduced from its Latinised name Vetus Ceppus in early charters.
The son of a British army officer, Seddon went to Dauntsey's School, an independent co-educational boarding school in the village of West Lavington in Wiltshire.
Teqüe also disputed international games facing Bordeaux Etudiants, Vascos de Baigorri and Stade Français (France), Birkenhead Park FC, Dauntsey's School (England), Garda (Ireland), University of Edinburg (Scotland), Walcha (Australia), Universidad Católica, Universidad de Chile and Chile national team.