Spanish Formosa was a colony of the Spanish Empire located in northern Taiwan from 1626 to 1642. Established to safeguard regional trade with the Philippines from Dutch interference, it was part of the Spanish East Indies based in Manila. However, the colony's significance diminished, and Spanish authorities in Manila were reluctant to invest further in its defense. After 17 years, the Dutch besieged and captured the last Spanish fortress, gaining control over a large portion of Taiwan. The territory was eventually ceded to the Dutch Republic during the Eighty Years' War.