Answer
The reign of Nikephoros II Phokas, the Byzantine emperor from 963 to 969, came to a violent end when he was assassinated on December 11, 969, at the hands of his nephew and subsequently successful usurper, John Tzimiskes, who led a group of conspirators. The plot unfolded at the imperial palace, where John managed to gain access and stab Nikephoros to death in his bedchamber.