Alexandria , because of its man-made bidirectional port between the mainland and the Pharos island , welcomed trade from the East and West , and soon found itself the international hub for trade , as well as the leading producer of papyrus and , soon enough , books . This detail is informed by the fact that Alexandria , because of its man-made bidirectional port between the mainland and the Pharos island , welcomed trade from the East and West , and soon found itself the international hub for trade , as well as the leading producer of papyrus and , soon enough , books .