sentences:  The alliance captured Keelung in northern Taiwan, but was forced to abandon it because of logistical difficulties and the inferiority of the Qing fleet when pitted against Koxinga's veteran sailors.During the Siege of Fort Zeelandia the Chinese took many Dutch prisoners, among them the Dutch missionary Antonius Hambroek and his wife, and two of their daughters.Koxinga sent Hambroek to Fort Zeelandia to persuade the garrison to surrender; if unsuccessful, Hambroek would be killed upon return.