Once Catholic emancipation was achieved, Daniel O’Connell campaigned for repeal of the Act of Union, which in 1801 had merged the Parliaments of the Kingdom of Great Britain and the Kingdom of Ireland to form the United Kingdom of Great Britain and Ireland. To campaign for repeal, O’Connell set up the Repeal Association. He argued for the re-creation of an independent Kingdom of Ireland to govern itself, with Queen Victoria as the Queen of Ireland.

To push for this, he held a series of ‘Monster Meetings’ throughout much of Ireland outside the Protestant and Unionist-dominated province of Ulster. They were so-called because each was attended by around 100,000 people. These rallies concerned the British Government and the Prime Minister, Sir Robert Peel, banned one such proposed monster meeting at Clontarf, Co Dublin, in 1843. This move was made after the biggest monster meeting was held at Tara.

Tara held great significance to the Irish population as it was the historic seat of the High Kings of Ireland. Clontarf was symbolic because of its association with the Battle of Clontarf in 1014, when the Irish King Brian Boru defeated his rival Máel Mórda, although Brian himself died during the battle. Despite appeals from his supporters, O’Connell refused to defy the authorities and he called off the meeting, as he was unwilling to risk bloodshed. He was arrested, charged with conspiracy and sentenced to a year’s imprisonment and a fine of £2,000, although he was released after three months by the House of Lords, which quashed the conviction and severely criticised the unfairness of the trial. Having deprived himself of his most potent weapon, the monster meeting, O’Connell with his health failing had no plan and dissension broke out in the Repeal Association.