al-Majid ya zama sananne a cikin shekarun 1980s da 1990s saboda rawar da ya taka a yakin da gwamnatin Iraqi ta yi a kan 'yan adawa na ciki, wato' yan tawayen Kurdawa na arewa, da 'yan tawayen Shia na kudanci. Matakan da aka yi wa al-Majid sun hada da fitarwa da kisan gilla; 'yan Iraqi sun kira shi "Chemical Ali" (علي الكيماوي, Ali-Kīmāwiiyy) saboda amfani da makamai masu guba a hare-haren da aka yi wa Kurdawa. An kama Al-Majid bayan mamayewar Iraki na 2003 kuma an zarge shi da laifukan yaki, laifukan cin zarafin bil'adama da kisan kare dangi. An yanke masa hukunci a watan Yunin 2007 kuma an yanke masa hukuncin kisa saboda kisan kare dangi na Kurdawa a cikin yakin al-Anfal na 1980s. An kashe shi a ranar 25 ga watan Janairu, 2007, kuma an yanke masa hukuncin kisa a ranar 4 ga watan Satumba, 2010.
Yuni na shekara ta 2007