Today in 1843, with a crowd of possibly a million heading for Clontarf the next day, Daniel O'Connell was told his rally was banned. All summer, his "monster meetings" demanding repeal of the Act of Union had rolled across Ireland. Dublin Castle was rattled. Clontarf was meant to be the crowning scene, and O'Connell chose the location for the historic significance. In 1014, Brian Boru had broken the army of Máel Mórda, King of Leinster, and his Viking allies there. The proclamation came late on Saturday, issued by the Lord Lieutenant, Earl de Grey. It accused the organisers of seeking to bring the government into hatred and contempt. By then the Castle had troops in position, artillery trained on the field and warships in the bay. Notices went up and riders were sent out through the night to turn back crowds already on the roads. O'Connell, 68 and a lifelong opponent of bloodshed, stood down. He told his followers to go home and not risk a conflict. Whether he saved lives or lost the movement is one of the great "what ifs? " of Irish history. A week later he was arrested for conspiracy, convicted in 1844 and jailed in Richmond Bridewell, until the House of Lords overturned the verdict. He walked out a hero. Yet the momentum was gone, and in 1846 the Young Irelanders, convinced that moral force had been tried and found wanting, broke from him. He died in Genoa the following year, as the Famine tightened its grip.