A century on, what was Ireland's partition & why does it still matter?

ust a hundred years ago, on May 3, 1921, Ireland was partitioned as an act passed by the British Parliament came into effect.

The 1920 Government of Ireland Act created two separate entities: Northern and Southern Ireland. The bill's original intention was to keep both under British rule but things did not quite go as planned.

26 of the island's 32 counties broke free from the United Kingdom to form an independent, Catholic-majority country which is known today as the Republic of Ireland. Six predominantly Protestant counties in the north stayed British.

A century later, Ireland is still split and the legacy of 1921 has endured.

What is the back story behind the partition of Ireland and why does it still matter today?

On this 100th anniversary, Euronews looks back at the history of Ireland and how it still informs the present and future on each side of the Irish border.

Ireland has been a contested territory since the 12th century. It was long dominated by its powerful British neighbour, ever since the Anglo-Norman invasion of 1169.

In the late 16th century, Britain implemented a plan to fully colonise Ireland in a bid to curb native Irish resistance. Thousands of Protestant settlers loyal to the British crown settled in plantations, especially in the northernmost province of Ulster.

The Irish Catholic population was displaced but did not convert to Protestantism. "Instead, two divided and antagonistic communities – each with its own culture, language, political allegiances, religious beliefs and economic histories – shared one region," wrote James Waller of Keene State College, who was a visiting research professor at the George J. Mitchell Institute for Global Peace, Justice and Security at Queen’s University in Belfast.

The conflict between the two rival communities continued to unfold in the following centuries. By the early 1900s, a nationalist, pro-independence movement emerged in the south.

"A more radical politics took over after the 1916 rebellion," said Eunan O'Halpin, professor of contemporary Irish history at Trinity College Dublin.

The bloody Irish republican insurrection began on Easter Monday, 1916 in Dublin as 1,500 Irishmen threw down an armed challenge against British rule. The rebellion was suppressed after just a week and its leaders executed.

The shift to more radical politics followed a failed attempt to implement self-government in Ireland.

"In 1914, just as World War I broke out, a law came into operation giving self-government to the entire island of Ireland, what was called Home Rule. That meant you were going to have a self-governing Ireland, but within the United Kingdom," O'Halpin explained.

Yet the idea of a self-governing province was fiercely opposed by unionists, predominantly Protestant, who feared it would be dominated by Catholics and nationalists.