 Located in the northern portion of the archipelago, it is the economic and political center of the nation, being home to the country's capital city, Manila, as well as Quezon City, the country's most populous city.With a population of 53 million , it contains 52.5% of the country's total population and is the fourth most populous island in the world.Luzon may also refer to one of the three primary island groups in the country.