 In 1177 , Saladin led a force of some 26 @,@ 000 soldiers , according to Crusader chronicler William of Tyre , into southern Palestine after hearing that most of the Kingdom of Jerusalem 's soldiers were besieging Harim north of Aleppo . Suddenly attacked by the Templars under Baldwin IV of Jerusalem near Ramla , the Ayyubid army was defeated at the Battle of Montgisard , with the majority of its troops killed . Saladin encamped at Homs the following year and a number of skirmishes between his forces , commanded by Farrukh Shah , and the Crusaders occurred . Undeterred , Saladin invaded the Crusader states from the west and defeated Baldwin at the Battle of Marj <unk> in 1179 . The following year , he destroyed the newly built Crusader castle of <unk> at the Battle of Jacob 's Ford . In the campaign of 1182 , he sparred with Baldwin again in the inconclusive Battle of Belvoir Castle in Kawkab al @-@ Hawa . The Ayyubid na 'ib ( deputy governor ) of Yemen , Uthman al @-@ <unk> , conquered the greater part of Hadramaut in 1180 , upon Turan @-@ Shah 's return to Yemen . 
