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
Easter Rising Document" was fake, MacNeill ordered the Volunteers to prepare to resist. Unbeknownst to MacNeill, the document had been forged by the Military Council to persuade moderates of the need for their planned uprising. It was an edited version of a real document outlining British plans in the event of conscription. That same day, the Military Council informed senior Volunteer officers that the rising would begin on Easter Sunday. However, it chose not to inform the rank-and-file, or moderates such as MacNeill, until the last minute. The following day, MacNeill got wind that a rising was about to be launched and