Government, Politics, Environment, Culture, Travel and tourism. History of Northern Mariana Islands, Culture of Northern Mariana Islands, tourism in Northern Mariana Islands, environment and tradition in Northern Mariana Islands, Introduction: The original inhabitants and dominant ethnic group of the Commonwealth of the Northern Mariana Islands (The full information on Northern Mariana Island, title” Northern Mariana Islands History, and Mariana Islands unification attempt” has the full detail)(all the Marianas except Guam) in western Micronesia refer to themselves as Chamorros ( tsamoros ). The term chamorri was used to designate the upper caste at the time of Magellan's arrival in 1521. The Spaniards heard this as chamurres and understood it to mean "friend." By 1668. Northern Mariana Islands History and Cultural Information and Travel Guide. Vacation package Book.