He was a son of High Chief Lakona of Oʻahu and his wife, Chiefess Alaʻikauakoko — daughter of a man named Pokai and his wife Hineuki. After his father's death, Kapae became the Chief of Oʻahu. Kapae married a woman named Wehina, whose parents are not known today. Wehina and Kapae's only known child was Chief Haka of Oahu.