King Tut's wife, his half sister (or niece) Ankhesenamun, seems to have been the marrying type.
In ancient Egypt it was acceptable for royalty to marry within the family, probably in order to help preserve dynastic succession. King Tut's predecessor Akhenaten and his queen, Nefertiti, had at least six children, but presumably no sons, as only girls are pictured in sculptures and reliefs of the family. This lack of boys in the main royal line (Akhenaten may have had a son or two, but by other, secondary, wives) made the question of dynastic succession a pressing problem.
Although it's difficult to sort out the tangled webs of late 18th-dynasty royal relationships, a likely story is this: Akhenaten himself married perhaps two of his own daughters by Nefertiti, one of them Ankhesenamun, in the hopes of producing a royal male heir. When Akhenaten died, Ankhesenamun may have been married off to the next king, mysterious Smenkhkare (if "he" was not actually a "she"—the idea has been floated that Smenkhkare might have been Nefertiti herself, ruling as a pharaoh). After Smenkhkare's disappearance from the records, the princess married young King Tutankhamun, who died at the age of 19 before he could father an heir.
Finally, when aged Aye, the vizier, took over as king in the wake of Tut's death, Ankhesenamun may have married him too. It's likely that Aye was either her grandfather or her great-uncle. This would mean that during a relatively short time in her youth she was married to her father, two of her half brothers (or one and an uncle), and her grandfather or great-uncle.
It's little wonder she sent letters abroad to the Hittites begging them to send her a young prince to marry and make king.