William Mcnaghton, Baron Erskine, was born in 1841, the only surviving son of the marriage of his father to Margaret. He joined the 7th Dragoon Guards at the age of 16, and moved to the 9th Lancers in 1861. He retired from the regular forces as a Captain in 1869, five years after his marriage to Caroline Alicia Martha Grimble
The Barony was conferred on his great-grandfather, who was the youngest son of Henry David, the tenth Earl of Buchan - one of the oldest Earldoms of Scotland. The first Baron was the Lord High Chancellor of England and was created Baron Erskine of Restormel Castle. The second Baron (grandfather of the man in this photograph) married the daughter of John Cadwallader of Philadelphia.