Under the Civil Authorities (Special Powers) Act (Northern Ireland) 1922, the Minister was enabled to make any regulation necessary to preserve or re-establish law and order in Northern Ireland.
The act specifically entitled him to ban parades, meetings, and publications, and to forbid inquests.
Parading was (and is) extremely contentious in Northern Ireland, and so the Minister was bound to anger one community or other regardless of what decision he made.
The parading issue may be the reason why the Home Affairs portfolio changed hands more often than most other Ministerial positions.
In 1970, the office was combined with that of Prime Minister of Northern Ireland with John Taylor serving as a cabinet rank junior minister, and then abolished along with the rest of the Northern Irish government in 1973.