Ancient Egyptian pharaonic culture stretched for millennia of kingdoms, dynasties, foreign invasions and civil war. The best known period today is the 18th Dynasty of the New Kingdom (c. 1549 – 1298 BC), thanks to the discovery of the tomb of Tutankhamun. But poor little buck-toothed Tut was a footnote in the history of the pharaohs, overshadowed by his predecessors.
One of his 18th Dynasty predecessors was Hatshepsut. Her father was Thutmose I, a great warrior king and Ahmose, his Chief Royal Wife (yes, it was an official title). Hatshepsut became the wife and queen of her half-brother, Thutmose II. It seems revolting to us today that step-siblings would marry, but the practice is rooted in how the 18th Dynasty pharaohs came to power.