In the year 3,960 BBY Revan (after drawling upon the Sith energies haunting the surface) defeats Mandalore the Ultimate at Malachor V in hand to hand combat and shortly after forces the Mandalorians to surrender activating his secret weapon the Mass Shadow Generator.
The end of the Mandalorian Wars also marked the end of Revan and Malak's alliance with the Jedi order and the birth of Revan's Sith Empire.