Guam, along with the Mariana Islands, were the first islands settled by humans in Remote Oceania. Incidentally it is also the first and the longest of the ocean-crossing voyages of the Austronesian peoples, and is separate from the later Polynesian settlement of the rest of Remote Oceania. They were first settled around 1500 to 1400 BC by migrants departing from the Philippines. This was followed by a second migration from the Caroline Islands by the first millennium AD, and a third migration from Island Southeast Asia (likely the Philippines or eastern Indonesia) by 900 AD.