<P> The ancestors of the Micronesians settled there over 4,000 years ago . A decentralized chieftain - based system eventually evolved into a more centralized economic and religious culture centered on Yap and Pohnpei . The prehistory of many Micronesian islands such as Yap are not known very well . </P> <P> On Pohnpei, pre-colonial history is divided into three eras: Mwehin Kawa or Mwehin Aramas (Period of Building, or Period of Peopling, before ca . 1100); Mwehin Sau Deleur (Period of the Lord of Deleur, ca . 1100 to ca . 1628); and Mwehin Nahnmwarki (Period of the Nahnmwarki, ca . 1628 to ca . 1885). Pohnpeian legend recounts that the Saudeleur rulers, the first to bring government to Pohnpei, were of foreign origin . The Saudeleur centralized form of absolute rule is characterized in Pohnpeian legend as becoming increasingly oppressive over several generations . Arbitrary and onerous demands, as well as a reputation for offending Pohnpeian deities, sowed resentment among Pohnpeians . The Saudeleur Dynasty ended with the invasion of Isokelekel, another semi-mythical foreigner, who replaced the Saudeleur rule with the more decentralized nahnmwarki system in existence today . Isokelekel is regarded as the creator of the modern Pohnpeian nahnmwarki social system and the father of the Pompeian people . </P> <P> Construction of Nan Madol, a megalithic complex made from basalt lava logs in Pohnpei began as early as 1200 CE . Nan Madol is offshore of Temwen Island near Pohnpei, consists of a series of small artificial islands linked by a network of canals, and is often called the Venice of the Pacific . It is located near the island of Pohnpei and was the ceremonial and political seat of the Saudeleur Dynasty that united Pohnpei's estimated 25,000 people until its centralized system collapsed amid the invasion of Isokelekel . Isokelekel and his descendants initially occupied the stone city, but later abandoned it . </P> <P> The first people of the Northern Mariana Islands navigated to the islands at some period between 4000 B.C. to 2000 B.C. from South - East Asia . They became known as the Chamorros, and spoke an Austronesian language called Chamorro . The ancient Chamorro left a number of megalithic ruins, including Latte stone . The Refaluwasch, or Carolinian, people came to the Marianas in the 1800s from the Caroline Islands . Micronesian colonists gradually settled the Marshall Islands during the 2nd millennium BC, with inter-island navigation made possible using traditional stick charts . </P>

Where did the migrants in the americas and oceania come from