John Redmond had agreed to suspend the introduction of Home Rule to Ireland until World War One had ended. This approach had been accepted by many in Ireland and tens of thousands had joined the British Army and fought in Europe. Some refused to accept it and fought the British in the Easter Rising of 1916. Few people were willing to support the rebels in Dublin and when they were arrested and paraded through the streets of Dublin prior to being sent to prison, they were jeered at by many Dubliners who had seen part of their city destroyed by the fighting that took place. However the execution of fifteen of the leaders, including Patrick Pearse and James Connolly, shocked many in Ireland - especially as they did not receive a formal and public trial and their executions were announced after they had been carried out. From the 'villains' of the piece, the rebel leaders suddenly became heroes to the Irish cause. After war ended in November 1918, the Irish question was to rear its head again.
In the 1918 'Coupon' Election, Sinn Fein had done well in the south. Sinn Fein was considered to be an extreme nationalist party - much more so than the Irish Nationalist Party led by John Redmond. In this election, the Irish Nationalists won only 6 seats while Sinn Fein won 73. Whereas John Redmond had been willing to work with the British government, Sinn Fein wanted an Ireland out of the British Empire - independent and self-governing. Its speedy rise to prominence is an indication of the anger that the British created with the execution of the rebel leaders - especially when the details leaked out of Connolly's execution. In 1914, Sinn Fein was a minor political force in Ireland; by the end of 1918, it was the leading nationalist force. For Sinn Fein, the whole issue of Home Rule was a non-starter. The rise of Sinn Fein also polarised the relationship between the north and with the south. By 1919, Ulster simply did not listen to Dublin.
The government responded to this by admitting that the 1912 bill was out-of-date and devised a new Home Rule bill for 1919. This stated that Ireland would govern itself within the Empire but in two separate parts - the south, and the six counties of the north (which was most, though not all, of the old province of Ulster). Each of the two parts would have a parliament in Dublin and Belfast and Ireland as a whole would still have MP's representing them in Westminster. The bill also proposed a Council of Ireland which would have representatives in it from both parliaments in Belfast and Dublin. The bill became an act in 1920. The north accepted the act and in 1921, the king opened the parliament of the six counties at Stormont.
However, the south did not accept one part of the act. Those members of Sinn Fein who had been elected MP's in the 'Coupon' Election in 1918, had refused to take up their seats at Westminster. Instead, in 1919, they established their own parliament (the Dail) in Dublin. They also declared an independent Ireland. It was around this time that the Irish Republican Army (founded from what had been the Irish Volunteers) started their campaign against any form of the British government in Ireland - be it in the south or north. This campaign was led by Michael Collins, who had fought in the Easter Rising. The IRA targeted anyone who was seen to be a symbol of British power in Ireland.
The government in London, responded by declaring both the Dail and Sinn Fein illegal. They also tolerated 'reinforcements' going to Ireland to assist the Royal Irish Constabulary. These 'reinforcements' were the Auxiliary Division (the 'Auxis') and the 'Black and Tans'. The 'Black and Tans' was made up of former soldiers, many of whom had experienced fighting in World War One. The 'Auxis' was exclusively made up of ex-army officers. Both units were involved in acts of extreme brutality against civilians which only served to make those who wanted independence even more keen on it. Violence led to more violence and it was clear that a political solution was needed if the escalating violence was to end. This came with the so-called 'Treaty with Sinn Fein' of 1921.