Secret police files dating from 1915 and 1916 are being made available online today by the National Archives for the first time.
Announcing their release, the Minister for Arts, Heritage and the Gaeltacht, Heather Humphreys, said they give a fascinating insight into the events leading up to the 1916 Rising.
The files are a series of daily reports by the Dublin Metropolitan Police.
They start in June 1915, and lead up to April 1916, just four days before the beginning of the Rising.
They include details of intelligence gathered at a number of key locations in the centre of Dublin, such as the shop of Thomas J Clarke at 75 Parnell Street.