 Despite incessant attacks and raids by the Moros, the surviving Christian populations of both missions still numbered over 3,000 by the time the Spanish returned.After having re-established lucrative trading agreements with the native kingdoms that dotted the area, nearby Zamboanga experienced a revival in its economy.The increasingly wealthy Spanish trading post in Zamboanga became an even more sought after prize for the Moro pirates of the era, so much so that the surrounding islands started to attract the attention of other foreign powers, and chief among these coveted islands was Basilan.