Complex sentence: El Jadida, previously known as "Mazagan" (Portuguese: "Mazagão"), was seized in 1502 by the Portuguese and controlled until 1769, when they abandoned Mazagão, their last territory in Morocco.
Split into simpler sentences: El Jadida, previously known as "Mazagan" (Portuguese: "Mazagão"), was seized by the Portuguese in 1502. The Portuguese would continue to controll the city until 1769, when they abandoned Mazagão, their last territory in Morocco.