* The Crusades led to the expansion of Christianity in Europe and the Middle East.
* The Crusades helped to create a sense of European identity.
* The Crusades led to the development of new trade routes and the exchange of goods and ideas between Europe and the Middle East.
* The Crusades led to the development of new technologies and military tactics.
* The Crusades led to the development of new forms of art and literature.
Negative consequences:
* The Crusades led to the deaths of millions of people.
* The Crusades led to the destruction of many cities and villages.
* The Crusades led to the displacement of many people.
* The Crusades led to the rise of religious intolerance and persecution.
* The Crusades led to the decline of the Byzantine Empire.