In the wake of the Easter Rising the British authorities had arrested nearly 3,000 people. Given that the prison system could not hold all those people it was decided that an internment camp for Irish prisoners would be used. The choice made was to use Frongoch Camp, near Balla, in north Wales, part of which had originally been built as a camp for German prisoners of the First World War. The remainder of the camp was built on a converted distillery. From 9 June 1916 the great majority of the male internees were moved there. At its busiest, in the summer of 1916, Frongoch held around 1,800 Irish prisoners.
From the autumn of 1916 the British authorities began releasing men and sending them home to Ireland. Frongoch was completely emptied by Christmas 1916 when the last of the internees was released. The site was never used again as a prison camp and was subsequently demolished.