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
Éamon de Valera victory must be allowed to rest for the moment with those who have destroyed the Republic. Other means must be sought to safeguard the nation's right." After this point many of the republicans were arrested in Free State "round ups" when they had come out of hiding and returned home. De Valera remained in hiding for several months after the ceasefire was declared; however, he emerged in August to stand for election in County Clare. Making a campaign appearance in Ennis on 15 August, de Valera was arrested on the platform and interned at Arbour Hill prison until 1924. After