 Francisco Combes, SJ, even then, an acknowledged historian of Mindanao, but to no avail.The Zamboanga fort was finally abandoned sometime in April 1663 by the last remaining Spanish troops, they were evacuated and returned to Cavite to help defend Manila's Intramuros from a threatened invasion by Chinese pirate Koxinga, which never happened.As fate will have it, the Chavacanos of Zamboanga and Pasangen, Jesuits included, will amazingly endure another 56 years (1662–1718) of isolated existence and proliferation amidst the hostile threat and return of the Moro Pirates who overtook and destroyed the abandoned fort.