Jerusalem has been always important to the Muslims because it contained the Dome of Rock, where our Beloved Prophet Muhammad [Sallal Laahu Alaieh Wa Sallam] ascended to heaven, and the Masjid al Aqsa.
By 1176 Hazrat Salaah ud din Aiyyuubi [Radiyal Laahu Anhu] had become a powerful Muslim ruler. Even though the Crusaders had signed a peace treaty, Reynald (a Christian prince) attacked a pilgrim caravan on its way to Hajj. He even planned to attack Makkah and Madinah to destroy the grave of Prophet Muhammad [Sallal Laahu Alaieh Wa Sallam]
Hazrat Salaah ud din Aiyyuubi [Radiyal Laahu Anhu] made the call for Jihaad and united all Muslim states to defend Islaam. The Crusaders gathered their armies and confronted the Sultaan at a place called Hattin.
Hazrat Salaah ud din Aiyyuubi [Radiyal Laahu Anhu] was very courageous. He took back Jerusalem in 1187 after 88 years of occupation; this would forever be remembered as his greatest achievement and it made him a Great Hero of Islaam. He will be remembered as the Rectifier of Faith because he brought faith back to the Holy Land.