 In 1933, other ecclesiastical territories were established in Mindanao, separating themselves from Zamboanga, the last of which was the Prelature of Ipil in 1979.Politically the two Zamboangas were just one province since the days of the Spanish era.Because of the many waves of migrations from the northern islands that occurred during the American era, the large province of Zamboanga was split up into two provinces in 1952.