The Troubles in Ulster of the 1920s was a period of conflict in the Irish province of Ulster, from June 1920 until June 1922, during and after the Irish War of Independence and the partition of Ireland (and specifically of Ulster). In Ulster, it was mainly a communal conflict between unionists, who wanted to remain part of the United Kingdom, and nationalists, who backed Irish independence: the unionists were mainly Ulster Protestants and the nationalists were mainly Irish Catholics. During this period, more than 500 people were killed in Belfast alone, 500 interned and 23,000 people were made homeless in the city, while approximately 50,000 people fled the province due to intimidation. Most of the victims were Nationalists (73%) with civilians being far more likely to be killed compared to the military, police or paramilitaries.
During the Irish War of Independence, the Irish Republican Army (IRA) attacked British security forces throughout the island; loyalists often attacked the Catholic community in retaliation. In July 1920, they drove 8,000 mostly Catholic workers out of the Belfast shipyards sparking sectarian violence in the city. That summer, violence also erupted in Derry, leaving twenty people dead, and there were mass burnings of Catholic property and expulsions of Catholics from their homes in Dromore, Lisburn and Banbridge.