The alii nui of Oûahu was the sovereign and supreme ruler of one of the four main Hawaiian Islands. The monarchs of the Island of Oahu, like those of the other islands, claim descent from WÃÂkea. Oahu was unified under the alii nui in the 15th century.
Nanaulu, a fourteenth generation descendant of Wakea, was the ancestor of Kumuhonua, the first known king of Oahu, brother of Moikeha, King of Kauai of the second dynasty. In 1783, Oahu was conquered by the King Kahekili II of Maui whose son Kalanikà «pule was, in turn, conquered by King Kamehameha I in 1795 at the Battle of Nuûuanu. Many times the kings of Oahu had hegemony over the island of Molokai and used it as summer getaway. It was Oahu who brought forth the first Mo'iwahine or Queen regnant of any of the Hawaiian Islands.