"Come then, with all your people and give battle with all your strength, so that all this treasure shall not fall into the hands of the Turks.. . . Therefore act while there is still time lest the kingdom of the Christians shall vanish from your sight. . . . And in your coming you will find your reward in heaven. ..
• An excerpt of a letter sent by Emperor Alexius Comnenus of the Byzantine
Empire to Pope Urban Il in 1093
Which event is referred to in this quotation?
Crusades
French Revolution
Glorious Revolution
Enlightenment