Easter Rising in putting the rising off for only a day, although it greatly reduced the number of Volunteers who turned out. British Naval Intelligence had been aware of the arms shipment, Casement's return, and the Easter date for the rising through radio messages between Germany and its embassy in the United States that were intercepted by the Royal Navy and deciphered in Room 40 of the Admiralty. The information was passed to the Under-Secretary for Ireland, Sir Matthew Nathan, on 17 April, but without revealing its source, and Nathan was doubtful about its accuracy. When news reached Dublin of the capture
History of Sinn Féin in the Easter Rising, despite being blamed by the British Government for it. The leaders of the Rising were looking for more than the Sinn Féin proposal of a separation stronger than Home Rule under a dual monarchy. Any group that disagreed with mainstream constitutional politics was branded 'Sinn Féin' by British commentators. Later in 1916, surviving members of the Rising led by Éamon de Valera joined and took control of the party. De Valera replaced Griffith as president. The party nearly split between its monarchist and republican wings at its 1917 Ard Fheis (conference) until a compromise motion was