Original: December July 9 Estevão da Gama departs Massawa , leaving behind 400 matchlock men and 150 slaves under his brother Christovão da Gama , with orders to assist the Emperor of Ethiopia to defeat Ahmad ibn Ibrihim al-Ghazi , who has invaded his Empire .
Simplified: July 9 - Estevão da Gama departs Massawa , leaving behind 400 matchlockmen and 150 slaves under his brother Christovão da Gama , with orders to assist the Emperor of Ethiopia defeat Ahmad ibn Ibrihim al-Ghazi who has invaded his Empire .