Irish Republic the Third Dáil, and all future institutions arising from it, as illegal. (See Second Dáil). The anti-Treaty side was then defeated in the Civil War. Most militant opposition to the Free State came to an end on 24 May 1923 when Frank Aiken, chief-of-staff of the IRA issued the order to "dump arms" and Éamon de Valera issued his address to the "Legion of the Rearguard". Éamon de Valera continued as president of the Sinn Féin political party. In March 1926, Éamon de Valera, along with most anti-Treaty politicians, founded a new party called 'Fianna Fáil' and ended their boycott
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