Discussions with a German fringe group by one of its leaders led to the promise of German help, which was offered aboard an arms ship, the Aud.  
Four Courts, the Shelbourne Hotel, and Arbour Hill Cemetery were three of the targeted sites.  Discussions with a German fringe group by one of its leaders led to the promise of German help, which was offered aboard an arms ship, the Aud.  However the secret negotiations were discovered, the ship was scuttled, and Roger Casement was captured.  Despite his arrest, the plans went forward and 1,560 volunteers and a 200-man contingent of the Citizen Army were mobilized.  Following the seizure of the general post office and a five-day standoff, Tom Clarke and Patrick Pearse surrendered and were subsequently executed.  FTP, identify this April 1916 Irish uprising named for the holiday during which it took place.
Four Courts, the Shelbourne Hotel, and Arbour Hill Cemetery were three of the targeted sites.  
Easter Rebellion