General Pong Krell wielded two double-bladed lightsabers, one blue and one green. She defeated the Sith, but only after he cut her sabre in two. She duelled Darth Malgus and his master on a ship in orbit above Korriban and escaped them, but went on to fight Malgus again on Alderaan. Satele Shan wielded a double-bladed lightsaber during the Old Republic era. When Maul resurfaced during the Clone Wars he wielded the same sabre, albeit with only one blade. With it he killed Qui-Gon Jinn and duelled Obi-Wan Kenobi, but the young Jedi cut his sabre in half and mortally wounded Maul.
Darth Maul wielded a double-bladed lightsaber in the years leading up to the Clone Wars.