What are the pros and cons of the crusades?

Answer 1

Pros - increase in trade, democratic thought, Renaissance, integrated previously isolated cultures, led to discoveries on Mediterranean trade routes, the first two crusades were in response to persecution of Christians in Jerusalem and resulted in a marked improvement in regards to their treatment. The Venetians involvement in the fourth crusade led to the sack of Constantinople, which had been a declining nation and a festering wound since Romanus Diogenes had lost Armenia to the Seljuk Turks.

Cons - trade coupled with the sanitation tech of the civilization led to the Black Death, democratic thought stimulated the 100 Years' War, the Reformation, and the 30 Years' War along with a mentality that wrought greater inhumanity in the French Revolution and what becomes a long history of abuses in what became the German nation perpetuating the Holocaust, the Renaissance led to imbalance in critical thinking that paved the way for modern warped and misguided perception of European history in the Middle Ages now being redressed by new scholarship in that field. A perfect case study for this is to research modern work on the Crusades.