He was born in 1901, the son of William George Maginess, a Lisburn solicitor, and his wife Mary Sarah Boyd.
[1] He was educated at The Wallace High School and Trinity College Dublin[2] from where he graduated with a law degree (LLD), and was called to the Northern Ireland bar in 1923.
Having served in the Royal Corps of Artillery during the Second World War he entered the Parliament of Northern Ireland in 1938 when he won the seat of Iveagh.
[citation needed] In the early 1950s however, Maginess became a hate figure for the Orange Order when he banned marches through Catholic areas in Counties Down and Londonderry.
[3] While Attorney General, Maginess was party to the case of Attorney General for Northern Ireland v Gallagher [1961] 3 All Er 299, which remains authority in the law of Northern Ireland and England & Wales for the principle that Dutch courage is not a defence in criminal law.