The 3rd Battalion, 4th Marines, a.k.a. "the Thundering Third" was a regular marine force during the Guild Wars. It was led by Colonel Javier Vanderspool, who also commanded the elite 321st Colonial Rangers Battalion. Recruits for the batallion were trained at Turaxis Prime. Many trainees who arrived on Turaxis II started under the Thundering Third, including Jim Raynor and Tychus Findlay. After their training, they would be reassigned to other units under Vanderspool, including the 321st Colonial Rangers Battalion.