Darth Malak, born as Alek, is the main antagonist of the video game Star Wars: Knights of the Old Republic and a posthumous antagonist in its sequel Star Wars: Knights of the Old Republic II: The Sith Lords.
He was originally a Jedi Knight and a prominent commander of the Republic Military who led the Galactic Republic to victory during the Mandalorian Wars. After the war's end, he and Revan chased the surviving remnants of the Mandalorian fleets into the Outer Rim where they met the Sith Emperor and were corrupted into becoming Sith Lords. He and Revan later established their own Sith Empire and Malak later took over and usurped power in his quest for galactic conquest.