Is there any hadith mentioning about a very big war before the arrival of Imam Mahdi?

There will be many wars taking place before the era of Imaam Mahdi.%0D%0AHereunder is one Hadith pertaining to that:%0D%0AHadhrat Umm Salma (Radhiallaahu Anha) reports that the blessed Rasul%0D%0A(Sallallaahu Alayhi Wasallam) said, 'There will be differences at the time%0D%0Aof the death of a Khalifah. Then a man of the inhabitants of Madinah will%0D%0Aflee to Makkah Mukarramah. Some people will come to him and take him out%0D%0Athough he will be unwilling. Then, they will pledge allegiance to him%0D%0Abetween the corners of Ka'bah (Hajar-e-Aswad) and Maqaame-e-Ebraahim. An%0D%0AArmy from Syria will be sent to fight him (Mahdi). They will sink to the%0D%0Aground in an open plain ground between Makkah Mukarramah and Madinah%0D%0AMunawwarah. When this will happen, the eminent saints of Syria and Iraq will%0D%0A%0Acome and take allegiance to him. Imaam Mahdi will distribute the wealth. He%0D%0Awill then govern the people according to the ways of Shari'ah and establish%0D%0AIslam on earth. He will live for seven years and then die and the Muslims%0D%0Awill perform his Janaaza.' (Abu Dawood pg.589)%0D%0A%0D%0Aand Allah Ta'ala Knows Best%0D%0A%0D%0AMufti Ebrahim Desai%0D%0AFATWA DEPT.