Taharqa constructed the biggest pyramid in the Nubian area (52 square meters at the base) at Nuri (near El-Kurru), as well as the most ornate Kushite rock-cut tomb. Taharqa was laid to rest with "about 1070 shabtis of varied sizes constructed of granite, green ankerite, and alabaster." His son, Nebka, continued his work. The Nuri Pyramid is one of the largest pyramids in Africa. It was built for King Taharqa, who ruled from 724 to 720 BC. The pyramid is made of dark gray granite and has three steps leading up to a flat top covered in smooth stone. Inside the pyramid, there are two chambers separated by a wall with eight pillars supporting it. There are no traces of paintings or sculpture on the walls or ceiling of either chamber. Underneath the pyramid is a large cache of artifacts that date back as far as 1200 BC. Taharqa's reign was very successful; he extended the borders of his kingdom until they reached the Nile River near modern Khartoum. However, internal strife caused him to be assassinated when an arrow shot into his chest during a war. His son, Nebka, only six years old at the time of his father's death, took over the kingdom. Nebka's mother, Queen Tetisheri, acted as regent while he was a child.