He invaded the island, ended the oppressive rule of the Saudeleur, and instituted the decentralized chiefdom (nahnmwarki) system that has survived through modern times.
In most versions of the Isokelekel legend, the Saudeleur rule had become oppressive under its abusive centralized social system, and its lords had offended the Thunder God Nan Sapwe, sealing the fate of the dynasty.
Some versions include that the ruler had also incensed other gods of the Pohnpeian pantheon and insulted a high priest who prophesied the Saudeleur's downfall.
These offenses, as well as the oppressive land ownership and tribute system of the Saudeleur, drew the ire of gods, humans, and animals alike.
In other versions, Isokelekel is the product of a youth deified by the Thunder God and a Dipwenpahnmei human or a pair of brothers avenging the murder of their father by the Saudeleur.
[4] According to tradition, Isokelekel stopped in several places throughout the eastern Caroline Islands en route to Pohnpei, including Ant Atoll near Kitti, Losap in the Mortlocks, and Pingelap.
According to some versions, it is on Ant Atoll that Isokelekel learns from his mother, a bird, an elderly lover, or by divination that his mission is to conquer Pohnpei.
[4] At Nahrihnnahnsapwe, a small reef island near Nan Madol, Isokelekel performed rites to reaffirm his intent to conquer Pohnpei.
The Saudeleur lord Saudemwohl was unaware the son of the Thunder God was aboard, however, he sent a fleet to welcome the visitors, receiving them as guests at Kalapuel, Nan Madol, offshore of the main island of Pohnpei.
[7][15] According to many versions, war broke out at Nan Madol after playing between local children and those from Isokelekel's canoe escalated into a fight.
[11][13] Another says that upon seeing the fortifications at Nan Madol, Isokelekel decided to withdraw, but was aided by a scorned and outcast woman from the ruling Saudeleur family.
Some state the lieutenant, named Nanparadak or Nahnapas, drove his spear into his foot to anchor it amid the retreat to rally the invaders.
[4] Legend recounts that the battle ended as Saudeleur lord Saudemwohl retreated ever uphill to a stream, where he transformed into a fish and remains today.
[4][9][15] Petersen (1990) presents an alternative analysis of the Isokelekel myth under which the historical leader invaded not Pohnpei, but only the region Madolenihmw.
[4] He summoned the elite of Pohnpei and surrounding islands to gather, to whom he announced a welcome regime change, and with whom he consulted in creating a new decentralized Pohnpeian political system.
[11][28] At Pahn Akuwalap, Isokelekel instituted a new political order, the sacred nahnmwarki, lesser nahnken, and priestly title system that remains in modern use on Pohnpei.
His supreme titles included Wasa Lapalap at Madolenihmw, Sangoro at Uh, Pwoudo at Nett, and Iso Eni at Sokehs.
[29][30] At Peikapw, a place of prayer, Isokelekel saw his reflection in a pool of water and, realizing his old age, decided to commit suicide.
[31] Petersen (1995) identifies a cultural theme of caution within the Isokelekel myth in relations with foreign powers, modernly applicable to the United States.
[14] Petersen (1990) also comments that "initiation of important events in Pohnpei mythology is often ascribed to outsiders," the prime example being Isokelekel and the Saudeleur.