Sinn Féin for nine years. (It merged with two other organisations to form Fine Gael in 1933.) Anti-Treaty Sinn Féin members continued to boycott the Dáil. At a special "Ard Fheis" in March 1926, de Valera proposed that elected members be allowed to take their seats in the Dáil if and when the controversial Oath of Allegiance was removed. When his motion was defeated, de Valera resigned from Sinn Féin; on 16 May 1926, he founded his own party, Fianna Fáil, which was dedicated to republicanising the Free State from within its political structures. He took most Sinn Féin TDs with him.
Éamon de Valera with the support of at least seven independents. The result was the First Inter-Party Government, with John A. Costello of Fine Gael as its compromise candidate for Taoiseach. Costello was duly nominated, consigning de Valera to opposition for the first time in 16 years. The following year, Costello declared Ireland as a republic, leaving partition as the most pressing political issue of the day. De Valera, now Leader of the Opposition, left the actual parliamentary practice of opposing the government to his deputy, Seán Lemass, and himself embarked on a world campaign to address the issue of partition. He visited