Complex sentence: In 1641, the Spanish were expelled from Taiwan by the Dutch, who rebuilt the Spanish compound Fort Santo Domingo into what is known today as Hung-Mao Cheng (紅毛城, literally, the Fortress of the Red-haired ones).
Split into simpler sentences: In 1641, the Spanish were expelled from Taiwan by the Dutch. It is today known as Hung-Mao Cheng (紅毛城, literally, the Fortress of the Red-haired ones).