The Irish Civil War is regarded as having commenced on this day in 1922 with an artillery strike on the Four Courts in Dublin.
Four Courts burning.
The Irish Republican Army had occupied the Four Courts since April 14, hoping to spark a conflict with the British. The Irish government ignored until British demands that it be addressed made that impossible. The Irish Free State borrowed two artillery pieces and 200 shells from the British and first demanded that the IRA remove itself from the building, which they refused to do.
What exactly occurred remains unclear. It's not certain who have the order to commence the bombardment. Some IRA survivors maintained they were actually getting ready to surrender when it commenced. Some suggest that British artillerymen in small numbers were provided with the guns, but if so, there's no definitive proof of that.
The event would spark the commencement of the Irish Civil War between the Irish Free State and the Irish Republican Army, which would last about a year.
The Syrian Federation, under the French mandate, came into existence.
Flag of the French mandate in Syria.