[1] His mother's family owned the Duffryn Estate in Glamorganshire and his maternal uncle was Henry Bruce, 1st Baron Aberdare.
His close friend, rackets partner and future England rugby union international Edward Fraser was a fellow Myrmidon Club member.
[2][3] Alleyne graduated with a fourth-class honours degree in 1877 and was called to the bar at the Inner Temple the following year.
He married Amy Constance Bright (1858–1933) in 1880 and he and his wife had one daughter, Stella Margaret Alleyne (born 1883) to whom the famous Green Fairy Book (1892), which was written by her aunt and uncle, was dedicated.
Alleyne died in November 1884 at Derby Hall in Matlock Bridge, Derbyshire at the age of 29.