In 1394 Gerald Dillon, Lord of Drumraney, was appointed Constable of Athlone Castle. He was the 2nd son of Robert Dillon, Lord of Drumraney, and his wife Anne, 2nd daughter of Sir Eustace le Poer.
Gerald married Emelia, daughter of the Earl of Desmond, and had 4 sons and 2 daughters. After Gerald, the Dillon family became hereditary Constables of Athlone Castle as the effectiveness of the Dublin government retreated eastwards into Leinster.
The names of Gerald's 4 sons and 2 daughters: 1. Sir Maurice, his heir; 2. Henry, a priest; 3. Sir James, ancestor of the Earls of Roscommon and the Barons of Clonbrock; 4. John; 5. Catherine; 6. Anne.
Gerald Dillon is #6 on John O'Hart's Irish Pedigrees (1892), Vol.2, "Barons of Drumrany":
Liam Cox, "The Dillons, Lords of Kilkenny West: Part One", in Ríocht na Midhe, Vol. XI (2000), p.72
D.B. Quinn & K.W. Nicholls, "Ireland in 1534", in T.W. Moody, F.X. Martin & F.J. Byrne (eds.), A New History of Ireland, Vol. III: Early Modern Ireland 1534-1691 (Oxford University Press, 2009), p.19