'David McIlhagger was born in Belfast and at the age of sixteen was apprentice with the Belfast Omnibus Company, during which period he attended evening classes at the Belfast School of Technology. In 1933 he graduated in electrical engineering from Queen's University, Belfast and in 1935 was appointed lecturer at the Belfast College of Technology. In 1942 he gained his doctorate from Queen's University and became lecturer there in 1955 and senior lecturer in 1960. In 1970 he was given a readership. He was a senior research fellow in Civil Engineering after retirement, and in 1977 joined the wave power research group. He contributed to the rebuilding of St.Barnabus (sic) Church, Belfast, after the war, and in 1963 was lay representative from Connor diocese at the Anglican Congress in Toronto. He was chairman of the local branch of the Institute of Electrical Engineers, and was the Northern Ireland Representative on the Council of the Benevolent Fund'.
The McIlhagger branch of the Clan is very well documented. Half of this family emigrated to Australia where sadly the name has died out, though some descendants there keep in touch with us. The name has very much survived and flourished in the British Isles, mostly in Northern Ireland. Robert George, born in 1795 had four children, the last of whom was David. David's son John emigrated to Australia, but his son George remained in Ireland where he became a Sergeant in the Royal Irish Constabulary, serving mostly in County Galway. He retired to Belfast where in 1912 he signed The Ulster Covenant and had his name entered in a number of annual Belfast Directories. George's eldest son, David (named, according to the Irish naming pattern, for his grandfather) married Elizabeth Louise Sherwood. David Sherwood was one of their sons. He certainly set an academic trend for a nephew of his is now a Professor of Engineering in the University of Ulster and several of the next generation are similarly distinguishing themselves.