During the Battle of Zeltros in 4 ABY, Bargthron, a Tof, served as the second-in-command. He answered to an unidentified Supreme within the invading forces.
Following the initial assault on Zeltros, the Tof successfully captured Den Siva, the leader of the Nagai forces stationed there. The Tof then coerced Den into betraying his own troops by making threats against Dani, a Zeltron who was, at the time, being held as a prisoner of the Tof.
The Supreme, who was leading the Tof invasion, placed Bargthron in command of Den and a Tof fleet. Their mission was to capture the remaining Nagai forces on Zeltros. Bargthron and his soldiers achieved a surprise attack against the Nagai, resulting in a massacre of both the Nagai and the Maccabree warriors. With resistance at a minimum, Bargthron proceeded to interrogate the Nagai prisoners, among whom was Han Solo. Bargthron soon came to the conclusion that the Nagai prisoners held no value for the Tof and gave the order for their immediate execution. However, Leia Organa and Dani had managed to escape their Tof captors, which proved to be a stroke of bad luck for Bargthron and his Tof troops. The two women eliminated Bargthron along with three members of his species, thus rescuing Solo and the remaining prisoners. The appearance of the women also served as a catalyst for a prisoner uprising, which included a large number of Zeltrons. The prisoners overcame their would-be executioners and destroyed Bargthron's armada. The invasion ultimately failed when the forces of the Alliance, the Hiromi Empire, the Nagai, and the indigenous Zeltrons united to drive them back.