Younger was the son of William Younger, of Auchen Castle, Moffat, and his wife Margaret (née Brown), from Sydney, Australia [REF].
He joined the British Army in 1884, taking up a commission with the 16th Lancers, but left in 1888[REF] and married Helen Caroline Gunter,[REF] the daughter of Sir Robert Gunter, 1st Baronet, the Conservative MP for Barkston Ash in Yorkshire.