For eight months following the Easter Rising over 1,800 Irish rebels were imprisoned in Frongoch, a former whiskey distillery in North Wales. It soon became a University of Revolution and among its notable alumni were Michael Collins & Richard Mulcahy. By December 1916 all the Irish prisoners had been repatriated and the camp was closed down.
Frongoch had initially held German prisoners-of-war but became much more high profile when the Irish rebels were interned there. Most of them were interned without any trial or chance to defend themselves and thus many who had not been supportive of the rebel cause initially, were converted during their internment.
This contemporary account of experience in the camp was an important part of the propaganda to win support for the nationalist cause in the lead up to the War of Independence