Éamon de Valera new line. However, a vote to accept the Free State Constitution (contingent on the abolition of the Oath of Allegiance) narrowly failed. Soon afterward, de Valera resigned from Sinn Féin and seriously considered leaving politics. However, one of his colleagues, Seán Lemass, convinced de Valera to found a new republican party. In March 1926, with Lemass, Constance Markievicz and others, de Valera formed a new party, Fianna Fáil ("The Warriors of Destiny"), a party that was to dominate 20th-century Irish politics. While Sinn Féin still held to an abstentionist line, Fianna Fáil was dedicated to republicanising the Free State from
Sinéad de Valera and Terence (Terry), and two daughters, Máirín and Emer. On 9 February 1936, Brian, then aged twenty, was killed in a riding accident in the Phoenix Park. Due to a combination of his imprisonment, political activities, and fundraising tours of the United States, the family saw relatively little of Éamon de Valera in the 1916-23 period. He was also away from home frequently during the early years of his political career. Sinéad de Valera played little or no public role during her husband's fifty years in public life. Sinéad de Valera wrote thirty one books for children in both English