Complex sentence: From the eleventh to the thirteenth century, European soldiers led by professional officers, the Crusades (1095--1291) fought against the Muslims provided large-scale warfare combat experience in the foreign, Holy Land of the Asian Middle East.
Split into simpler sentences: From the eleventh to the thirteenth century, European soldiers led by professional officers, fought against the Muslims in the Crusades (1095--1291). These officers provided large-scale warfare combat experience in the foreign, Holy Land of the Asian Middle East.