 Complete the following phrase:  Marches marking the Ulster Protestant celebration The Twelfth in July 1969 led to riots and violent clashes in Belfast, Derry and elsewhere. The following month a three-day riot began in the Catholic Bogside area of Derry, following a march by the Protestant Apprentice Boys of Derry. The Battle of the Bogside caused Catholics in Belfast to riot in solidarity with the Bogsiders and to try to prevent RUC reinforcements being sent to Derry, sparking retaliation by Protestant mobs. The subsequent arson attacks, damage to property and intimidation forced 1,505 Catholic families and 315 Protestant families to leave their homes in Belfast in the Northern Ireland riots of August 1969 The riots resulted in 275 buildings being destroyed or requiring major repairs, 83.5 of them occupied by Catholics. A number of people were killed on both sides, some by the police, and the British Army were 