A single tooth has led to the identification of ancient Egypt's most powerful woman. Egyptologists were sure the pharaoh Hatshepsut was one of two female mummies found a century ago in the same tomb in the Valley of the Kings, but which one? The answer emerged when a broken tooth in a box holding the pharaoh's internal organs was matched to a gap in the mummy's teeth. Hatshepsut ruled as pharaoh for 21 years during the 18th Dynasty (1550 to 1292 B.C.) Hers was a prosperous time, and Egyptologist Dennis Forbes wrote in 2005 that she was perhaps "history's first great woman" and "without a doubt... the first great female ruler." Examination of her mummy revealed she was about 50 years old, overweight, and diabetic when she died of bone cancer.