An increased presence of Christians in the Levant during the Middle Ages. the development of military orders. a polarisation of the East and West based on religious differences. the specific application of religious goals to warfare in the Levant, Iberian peninsula, and Baltic region, in particular. the increased role and prestige of the popes and the Catholic Church in secular affairs. the souring of relations between the West and the Byzantine Empire leading, ultimately, to the latter’s destruction. an increase in the power of the royal houses of Europe. a stronger collective cultural identity in Europe. an increase in xenophobia and intolerance between Christians and Muslims, and between Christians and Jews, heretics and pagans. an increase in international trade and exchange of ideas and technology. an increase in the power of such Italian states as Venice, Genoa, and Pisa. the appropriation of many Christian relics to Europe. the use of a religious historical precedent to justify colonialism, warfare and terrorism.
The reason why many historians regard the printing press as the most important invention of the past millennium is because it allowed for thoughts and ideas--and thus things like revolutions and large-scale changes--to spread far more quickly and effectively.
