After allowing discipline at the southern forts to deteriorate, the government eventually withdrew its garrisons and, not long afterward, the forts were reoccupied by the rising Nubian state of Kush. In the north, Lower Egypt was overrun by the Hyksos, a Semitic people from across the Sinai. An independent line of kings created Dynasty XIV that arose in the western Delta during later Dynasty XIII. According to Manetho, into this unstable mix came invaders from the east called the Hyksos who seized Egypt "without striking a blow; and having overpowered the rulers of the land, they then burned our cities ruthlessly, razed to the ground the temples of gods..." Their regime, called Dynasty XV, was claimed to have replaced Dynasties XIII and XIV in most of the country.