Why did alexandria become a major center of learning

Because Alexandria owned the the Great Library which contained the scrolls and and other information that is very crucial in the knowledge of the world. However, unfortunately, it was famous for being burned down with only a few of its scroll saved. Alexandria also houses different institutions such as: Le Collège de la Mère de Dieu, Collège Notre Dame de Sion, Collège Saint Marc, Ecoles des Soeurs Franciscaines, École Gérard, École Saint Gabriel, École Saint-Vincent de Paul, École saint joseph, École Sainte Catherine, and Institution Sainte Jeanne-Antide and many more.