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 that Proportional Representation had been responsible for the instability that had characterised much of the post war period. A constitutional referendum to ratify this was defeated by the people. One aspect of de Valera's legacy is that since the foundation of the state, a de Valera has nearly always served in Dáil Éireann. Éamon de Valera served until 1959, his son, Vivion de Valera, was also a Teachta Dála (TD). Éamon Ó Cuív, his grandson, is currently a member of the Dáil while his granddaughter, Síle de Valera is a former TD. Both have served in ministries in the Irish