The First Crusade 

The First Crusade was led by Godfrey de Bouillon.  They entered Jerusalem in 1099. (See "The Templar Pirates" page 26)

The First Crusade started in 1095 when Pope Urban II requested the forming of a Christian Army to capture the Holy Land from the Muslims. (See "Templars in America" page 13)  Christians and Muslims have been murdering each other ever since and probably will continue until one of these two religions kill of ever last member of the other religion.  Then the 'winner' will probably try to kill of all members of some other religion.  Killing people for their God seems to be the main goal of Expansionist Religions. although the accumulation of money and other assets may also be the main goal.

Perhaps the first major battle between the two Expansionist Religions, Christianity and Islam.