What were the effects of the …

The Crusades had the following effects in Asia.
1. They led to the intensification of violence in West Asia, thereby leading to the loss of many lives.
2. They weakened the Byzantine empire, based in Constantinople, and contributed to its eventual defeat at the hands of the Ottomans.
3. They led to the entry of new population groups from Europe into West Asia. For example, people from French Levantine arrived and settled down in present day Lebanon, Palestine and Turkey.
4. They led to the emergence of short lived Christian states in Palestine based in Jerusalem.
The Crusades had the following effects on Europe.
1. They reopened the Mediterranean sea to commerce and contributed to the rise of Italian trading city states like Venice and Genoa.
2. They increased the power of the Catholic church in Europe and increased its ability to create wars and inflict violence on the common people.
3. They became a source of tales about heroism, valour and chivalry in Europe.