Person
Ibn Muljim
ابن ملجم
d. 661 CE
Ibn Muljim was a Kharijite dissident who assassinated Ali in 661 in retaliation for the defeat at Nahrawan.
Significance
Assassin of Caliph Ali
Reputation in tradition
condemned
Stated motivation
Revenge for Kharijite defeat at Nahrawan
Sources: Wikipedia and classical Islamic biographical literature compiled by automated researchers. Every page is being continuously refined — if something looks off, please check back in a few days.