What led to Ireland being divided? Professor Heather Jones explains...


A worsening devolution crisis

Before partition, all of Ireland was part of the United Kingdom and governed by the British government in London. However, by the First World War, Irish nationalists, who were predominantly Roman Catholic, had succeeded in getting legislation passed for Home Rule – devolved government for Ireland within the UK. But Home Rule’s imminent implementation was suspended when the First World War broke out in 1914.

Home Rule was vehemently opposed by Ireland’s unionists, mainly Protestants, mostly based in the north, who wanted no change to Ireland’s direct governance by Westminster. Religious differences mattered greatly in Ireland and many unionists feared that ‘Home Rule’ would be ‘Rome Rule’, leaving them as a religious minority under a Dublin parliament dominated by Catholicism.

The situation dramatically radicalised when, at Easter 1916, an Irish republican uprising broke out in Dublin. Its leaders believed devolution – Home Rule – did not go far enough. They wanted a complete end to British rule in Ireland and an all-Ireland republic outside of the UK.

The rising was quickly suppressed, but the British execution of its leaders led Irish nationalists to abandon Home Rule in favour of seeking full independence: in 1918, nationalists voted overwhelmingly for a pro-republic political party, Sinn Féin.

More like this

In 1919, supporters of the rising mobilised an Irish Republican Army (IRA) and launched a war for an independent Irish republic. This brutal guerrilla conflict of ambush and reprisals saw Britain lose control of nationalist areas, while sectarian violence also broke out, particularly in the northern city of Belfast.

There were unionists all across Ireland, but they were weak in numbers in the south and west. By contrast, in Ireland’s northern province of Ulster, unionism was politically very well-organised and had powerful supporters in London and a large population base. From 1912, Ulster Unionism became the most important strand of the island’s unionist movement. Yet those supporting Irish independence never developed a coherent policy towards Ulster Unionism, underestimating its strength and rejecting unionists’ British identity.

Republican leader Éamon de Valera’s proposed solution was as follows: “The so-called Ulster difficulty is purely artificial as far as Ireland itself is concerned. It is an accident arising out of the British connection, and will disappear with it.”

The Government of Ireland Act and the creation of Northern Ireland

Desperate to end the war in Ireland, which was damaging Britain’s international reputation, the British government proposed a solution: two home rule parliaments, one in Dublin and one in Belfast. The details were outlined in the Government of Ireland Act in late 1920.

Fearful of the violent campaign for an independent Irish republic, many Ulster unionists, who had been adamantly against any change to direct British rule, accepted this idea. It would create a border between the territory governed by the devolved northern home rule parliament and the southern one, but both areas were to remain within the United Kingdom.

The border was also designed so that only a part of the historic province of Ulster – six counties chosen because they represented the Protestant Ulster heartlands which had a clear unionist majority – would be governed by the northern parliament, ensuring unionists would dominate it.

In May 1921, this new Northern Ireland officially came into being. Sir James Craig, Northern Ireland’s new prime minister, stated: “I’m going to sit on Ulster like a rock, we are content with what we have got.” Home Rule’s greatest opponents in Ireland – Ulster unionists – had become its most fervent supporters.

Map of the partition of Ireland; the division of the island of Ireland into two distinct territories; Northern Ireland and Southern Ireland in 1921. (Photo by: Photo 12/Universal Images Group via Getty Images)
Map showing the partition of Ireland in 1921; the division of the island into two distinct territories. (Photo by Photo 12/Universal Images Group via Getty Images)

The northern parliament took root, helped by heavy spending on security forces to support it from London. By contrast, its southern equivalent was a failure, proving impossible to start up as nationalists boycotted it. When the British government tried to open its new Dublin Home Rule parliament after holding elections in 1921, only four elected representatives of its House of Commons – all southern unionists – showed up. The rest of those elected took seats in the Dáil instead, a rival clandestine parliament that Irish republicans had established in January 1919 as part of their planned republic, and which, by 1921, despite being illegal, had usurped many state powers and was thriving.

Between 1920 and 1922, an estimated 550 people died in the six counties – approximately 300 Catholics, 170 Protestants and 80 members of the security forces

Former British prime minister Herbert Asquith quipped that the Government of Ireland Act gave “to Ulster a Parliament which it did not want, and to the remaining three-quarters of Ireland a Parliament which it would not have”.

Unable to get politicians willing to sit in it, the operation of the southern parliament was effectively suspended. The Government of Ireland Act thus proved impossible to implement in the south.

Meanwhile, the new northern regime faced the problem of ongoing violence. The IRA waged a campaign against it, while sectarian violence, which had worsened from when the plans for the Government of Ireland Act first emerged, continued to rip apart northern society. Between 1920 and 1922, an estimated 550 people died in the six counties – approximately 300 Catholics, 170 Protestants and 80 members of the security forces.

Unionists believed this period to be one of existential threat to their survival on the island. Little wonder that when King George V, opening the new Northern Ireland parliament in June 1921, before a unionist audience, called for peace and reconciliation, some of the women present wept.

The epicentre of the violence was Belfast where, in July 1921, there were gun battles in the city between the IRA and pro-partition loyalist paramilitaries. Belfast’s Catholics made up only a quarter of the city’s population and were particularly vulnerable; thousands were expelled from their shipyard jobs and as many as 23,000 from their homes.

Unable to implement the southern home rule parliament, the British government changed policy. In December 1921, an Anglo-Irish Treaty was agreed. It ended British rule in the 26 counties that had been meant to be under the southern devolved Home Rule parliament. This area now became an independent Irish Free State and, unlike Northern Ireland, left the UK. What had been intended to be an internal border within the UK now became an international one.

However, the Free State was not a republic but an independent dominion within the British empire, and the British monarch remained the Head of State; the British government had only agreed to accepting Irish independence on these terms. This outcome split Irish nationalism, leading to a civil war, which lasted until 1923 and weakened the IRA’s campaign to destabilise Northern Ireland, allowing the new northern regime to consolidate.

The aftermath of partition

The first year of partition was a bloody one. Sectarian atrocities continued into 1922, including Catholic children killed in Weaver street in Belfast by a bomb thrown at them and an IRA massacre of Protestant villagers at Altnaveigh. As the Guardian newspaper noted in June 1922: “We cannot now pretend that this partition idea has worked: the whole world would burst into laughter at the suggestion.”

Partition created two new fearful minorities – southern unionists and northern nationalists. Tens of thousands chose or were forced to move; refugees arrived in Britain, Belfast and Dublin. Ulster unionists felt guilt at the fate of those unionists left as a minority in the rest of Ireland, who had to integrate into the new Irish Free State as best they could; some emigrated to Britain or Northern Ireland, while others slowly assimilated.

Yet it was Ireland’s other new minority – northern Catholic nationalists left within the UK – that proved the most vulnerable. Safeguards put in place for them at the time of partition, such as proportional representation in elections to the northern parliament, were swiftly removed; they had virtually no protection from rampant discrimination and sectarian violence. Successive governments in Dublin also pursued a policy of non-recognition of Northern Ireland and demanded northern nationalists boycott it, heightening the minority’s difficulties.

The British government hoped that the border would only be temporary: both the Government of Ireland Act and the Anglo-Irish Treaty were designed to facilitate future reunification of the island if this ever became possible. Nationalists believed Northern Ireland was too small to economically survive; after all, designed to fit religious demographics, the border made little economic sense and cut several key towns in the north off from their market hinterlands.

In 1925, a Boundary Commission, established to fix the border’s permanent geographic location, effectively approved it as it stood. It ran through lakes, farms, and even houses. Its idiosyncrasies matched those of the implementation of partition itself. Most infrastructure split in two – railways, education, the postal service – and entirely new police forces were founded in the north and the south.

But a range of civic organisations, including the Roman Catholic and Anglican Churches, the Irish Dental Association, the Institute of Chartered Accountants in Ireland, the Royal Irish Academy and Irish rugby continued to operate on an all-Ireland basis. Such connections became precious conduits of social communication between the two Irelands as the relationship between northern and southern governments proved glacial.

By the time the Irish Free State unilaterally declared itself a republic in 1949, the border – a source of bitterness for nationalists – had become an integral aspect of northern unionist identity which viewed Northern Ireland’s survival as interwoven with unionism’s own.


Heather Jones is professor of modern and contemporary history at University College London