British Army Field Marshal Sir Henry Wilson was assassinated on June 22, 1922, by the Irish Republican Army (IRA) in London. As a prominent military figure, Wilson had been vocal against Irish republicanism, having served extensively during the Irish War of Independence. His assassination was part of a larger wave of violence as Ireland was on the brink of civil war, following the signing of the Anglo-Irish Treaty in December 1921 that led to the partition of Ireland and the establishment of the Irish Free State, which many republicans opposed.

The attack took place as Wilson was walking to his office and he was ambushed by two gunmen, who fired five shots at him, fatally wounding him. This act of violence was not only a targeted assassination but also symbolized the fierce opposition that pro-Treaty forces faced from anti-Treaty elements within Ireland. It galvanized public opinion and escalated tensions, catalyzing the divide that would turn into a fully-fledged civil war in Ireland, marked by radical actions from both sides.

In the aftermath, Wilson's assassination was seen as a turning point. It marked a significant intensification of violence between pro- and anti-Treaty factions, leading to numerous reprisals and battles throughout Ireland as the civil war set in motion a cycle of violence that plagued the nation. Wilson’s death highlighted the complexities of the political landscape in Ireland during this tumultuous period, ultimately leading to a restructuring of political alliances and ongoing conflicts that would last for decades.