Wilhelm was a friend of Archduke Franz Ferdinand of Austria, and he was deeply shocked by his assassination on 28 June 1914. Wilhelm offered to support Austria-Hungary in crushing the Black Hand, the secret organisation that had plotted the killing, and even sanctioned the use of force by Austria against the perceived source of the movement—Serbia (this is often called "the blank cheque"). He wanted to remain in Berlin until the crisis was resolved, but his courtiers persuaded him instead to go on his annual cruise of the North Sea on 6 July 1914. Wilhelm made erratic attempts to stay on top of the crisis via telegram, and when the Austro-Hungarian ultimatum was delivered to Serbia, he hurried back to Berlin. He reached Berlin on 28 July, read a copy of the Serbian reply, and wrote on it: