Why is Roman Catholicism the dominant religion in the Philippines?

Roman Catholicism is the dominant religion in the Philippines due to its establishment during the Spanish colonial period, which began in the 16th century. Spanish missionaries actively worked to convert the local population, and Manila became an ecclesiastical capital. While other Christian denominations and Islam are present, Roman Catholicism remains the faith of approximately four-fifths of Filipinos. The religion's influence grew throughout the 20th century with increased local leadership and engagement in the country's social and political life.123