He joined the Ballymacelligott company of the Irish Volunteers in 1914 and was involved in an abortive attempt by Roger Casement to land arms for the Easter Rising at Banna Strand in Kerry. After the rebellion he was interned by the British at Frongoch internment camp in Wales for his role in the events. In April 1918, he led an arms raid on Gortatlea Royal Irish Constabulary barracks in which two Volunteers were killed. It was one of the first acts of guerrilla warfare in the period.