Lakan originally referred to a rank in the pre-Hispanic Filipino nobility in the island of Luzon, which means "paramount ruler." It has been suggested that this rank is equivalent to that of Rajah, and that different ethnic groups either used one term or the other, or used the two words interchangeably. In Visayas and Mindanao, this rank is "Datu". "Sultan" was also used in the most developed and complex Islamized principalities of Mindanao.