What role did the muslim leader salah-al-din (saladin) play in the crusades?

Saladin is a Muslim and sultan leader who commanded Islamic forces during European crusades. His power included Egypt, Syria, Mesopotamia, Hejaz, Yemen and other parts of North Africa. Some of his contributions are the following:  

*He triumphed against the crusaders at Battle of Hattin on 1187 making a re-conquest to Holy Land cities in the East.  

*Though failed to win against King Richard I (the Lionheart) of England, he was able to made truce continuing Muslim control over Jerusalem.  

*He keeps having holy wars to exterminate political and military influence of Christian in Jerusalem.

The four conditions that brought about the birth of Sociology in Europe are: French Revolution, Industrial Revolution, Imperialism, and the success of the Natural sciences.

Explanation:

There was shift from agriculture to factory production during The Industrial Revolution which resulted in a lot of changes in the lives of the people such as bad working conditions, increase in Urbanization etc.

Their were also the introduction of more democratic forms of government during the French Revolutions, this introduced the inalienable rights of individuals.

August Comte is referred to as the Father of Sociology, He studied the society as a result of the changes that occurred in the French and Industrial Revolutions. These changes include; Aristocrats lost their status and money, the class system in France changed suddenly, people left agriculture and moved to the cities to find jobs and they were paid low wages under stressful working conditions. These changes made Comte to decide that a new science is needed which he called 'Sociology'.