The Sunningdale Agreement was an attempt to end the Troubles in Northern Ireland by forcing unionists to share power with nationalists.] The Agreement led to the establishment of a power-sharing cross-community Northern Ireland Executive and a cross-border Council of Ireland. The Agreement was signed at the Civil Service College (now the National School of Government) in Sunningdale Park located in Sunningdale, Berkshire, on 9 December 1973. Unionist opposition, violence and a loyalist general strike caused the collapse of the Agreement in May 1974.

Northern Ireland Assembly:

On 20 March 1973, the British government published a white paper which proposed a 78-member Northern Ireland Assembly, to be elected by proportional representation. The British government would retain control over law and order, and a Council of Ireland would give the Republic of Ireland and Northern Ireland a voice in each other's affairs. This assembly was to replace the suspended Stormont Parliament, but it was hoped that it would not be dominated by the Ulster Unionist Party (UUP) in the same way, and would thus be acceptable to nationalists.

The Northern Ireland Assembly Bill resulting from the White paper became law on 3 May 1973, and elections for the new assembly were held on 28 June. The agreement was supported by the nationalist Social Democratic and Labour Party (SDLP), the unionist UUP and the moderate unionist and cross-community Alliance Party. The pro-agreement parties won a clear majority of seats (52 to 26), but a substantial minority inside the Ulster Unionist Party opposed the agreement.

Republicans boycotted the elections, and the IRA continued its campaign of opposition throughout the outcome.

Power-sharing Executive:

After the Assembly elections, negotiations between the pro-White Paper parties on the formation of a "power-sharing Executive" began. The main concerns were internment, policing and the question of a Council of Ireland.

On 21 November, agreement was reached on a voluntary coalition of pro-agreement parties. Prominent members of the Executive included former Unionist Prime Minister Brian Faulkner as Chief Executive, SDLP leader Gerry Fitt as Deputy Chief Executive, future Nobel Laureate and SDLP leader John Hume as Minister for Commerce and leader of the Alliance Party Oliver Napier as Legal Minister and head of the Office of Law Reform. The UUP was deeply divided - its Standing Committee voted to participate in the executive by a margin of only 132 to 105. The end of majoritarianism caused great strife in the UUP.

Council of Ireland:

Provisions for a Council of Ireland existed in the Government of Ireland Act 1920, but these had never been enacted. Unionists resented the idea of any "interference" by the Republic of Ireland in their newly established region. In 1973, after agreement had been reached on the formation of an executive, agreement was sought to re-establish a Council of Ireland to stimulate co-operation with the Republic of Ireland. Talks were held between 6 December and 9 December in the Berkshire town of Sunningdale between the British Prime Minister Edward Heath, the Irish Taoiseach Liam Cosgrave and the three pro-agreement parties.

The talks agreed on a two-part Council of Ireland:

The Council of Ministers was to be composed of seven members from the power-sharing executive, and seven members from the Irish Government. It was to have "executive and harmonising functions and a consultative role". The Consultative Assembly was to be made up of 30 members from Dáil Éireann and 30 members from the Northern Ireland Assembly. It was to have "advisory and review functions" only.

On 9 December, a communiqué announcing the agreement was issued, which later became known as the Sunningdale Agreement.

Reaction to the Agreement:
It was eventually agreed that the executive functions of the Council would be limited to "tourism, conservation, and aspects of animal health", but this did not reassure the unionists, who saw any influence by the Republic over Northern affairs as a step closer to a united Ireland. They saw their fears confirmed when SDLP councillor Hugh Logue publicly described the Council of Ireland as "the vehicle that would trundle unionists into a united Ireland" in a speech at Trinity College, Dublin. On 10 December, the day after the agreement was announced, loyalist paramilitaries formed the Ulster Army Council - a coalition of loyalist paramilitary groups, including the Ulster Defence Association and the Ulster Volunteer Force, which would oppose the agreement.
In January 1974, the Ulster Unionist Party narrowly voted against continued participation in the Assembly and Faulkner resigned as leader, to be succeeded by the anti-Sunningdale Harry West. The following month a general election took place. The Ulster Unionists formed the United Ulster Unionist Council (UUUC) as a coalition of anti-agreement unionists with the Vanguard Progressive Unionist Party and the Democratic Unionist Party to stand a single anti-Sunningdale candidate in each constituency. The pro-Sunningdale parties, the SDLP, the Alliance, the Northern Ireland Labour Party and the "Pro Assembly Unionists" made up of Faulkner's supporters, were disunited and ran candidates against one another. When the results were declared, the UUUC had captured eleven of the twelve constituencies, several of which had been won on split votes. Only West Belfast returned a pro-Sunningdale MP (Gerry Fitt). The UUUC declared that this represented a democratic rejection of the Sunningdale Assembly and Executive, and sought to bring them down by any means possible.

In March 1974, pro-agreement unionists withdrew their support for the agreement, calling for the Republic of Ireland to remove the Articles 2 and 3 of its constitution first (these Articles would not be revised until the Good Friday Agreement of 1998).

Seamus Mallon of the SDLP famously declared that the Good Friday Agreement of 1998 was "Sunningdale for slow learners" Marian Price of the 32CSM stated that the Good Friday Agreement was "Sunningdale for retards" in reference to Mallon's quote.

Collapse of the Agreement:

Following the defeat of a motion condemning power-sharing in the Northern Ireland Assembly, a loyalist organization called the Ulster Workers' Council called a general strike for 15 May. After two weeks of barricades, shortages, rioting and intimidation, Brian Faulkner resigned as Chief Executive and the Sunningdale Agreement collapsed on 28 May 1974.

The strike succeeded because the British were reluctant to use force at an early stage and later the use of force was vetoed by the unionists in the Executive.

The most crippling aspect of the strike was its effect on electricity supply - the Ballylumford power station controlled Belfast's electricity and that of most of Northern Ireland. The workforce was overwhelmingly Protestant and effective control was firmly in the hands of UWC. John Hume's plan to cut the Northern Ireland electricity grid in two and rely on the power generated by Coolkeeragh Power Station (where many Catholics worked) to keep Derry and environs in business while undermining the unionist strikers in the east was rejected by the British Secretary of State Merlyn Rees.

In later strikes the security forces were prepared to use force immediately and so intimidatory barricades - essential to the success of the UWC strike - were suppressed from the outse