After Plagueis murdered his master on Bal'demnic in 67 BBY, his lightsaber continued to be in his possession, even at the time he trained Palpatine as his apprentice. When Palpatine executed Pax Teem as retribution for outwitting him and his master he used Plagueis's lightsaber. He noted that it had been built for a larger grip and had to use two hands to effectively wield it.