The siege dragged on without much progress, punctuated by frequent sallies on the part of the besieged; one of these claimed the life of their king. After two months the Khazars retreated to the steppe, promising to return by the autumn.[14] Tong Yabghu left young Böri Shad, either his son or nephew, in charge of the remaining forty thousand which were to assist Heraclius during the siege. Before long these departed as well, leaving the Byzantines to continue the siege alone and prompting jeers from the besieged.[15]