In 1668 the islands were renamed by Padre Diego Luis de San Vitores as Las Marianas after Mariana of Austria, widow of Spain's Philip IV.Most of the islands' native population (90%-95%)6 - died from the diseases brought by the Spanish or intermarried with non-Chamorro settlers under Spanish rule, but new settlers, primarily from the Philippines and the Caroline Islands, were brought in to repopulate the islands. Despite this, the Chamorro population did gradually resurge, and Chamorro, Filipino and Carolinian language and ethnic differences remain basically distinct in the Marianas. To facilitate cultural and religious assimilation, Spanish colonists forced the Chamorros to be concentrated on Guam for a period of time. By the time Chamorros were allowed to return to the present-day Northern Marianas, Carolinians (from present-day eastern Yap State and western Chuuk State) had settled in the Marianas. Hence Carolinians and Chamorros are both considered as indigenous to the Northern Marianas and both languages are official in the commonwealth (but not on Guam).