Grann was a general serving the Sith Empire. He was a male Human during the Galactic War. It was in 3640 BBY that Grann, alongside General Merion, found themselves stationed on Corellia. There, they spearheaded the Imperial forces' successful capture of Guardian Hold Four, an operation aided by the Children of the Emperor. Nevertheless, the Barsen'thor, with the help of the Rift Alliance, managed to retake the base. They triumphed over both the Imperial Guard and the Child of the Emperor, Daresha, who was stationed there. Subsequently, both generals were taken prisoner. Grann opted to collaborate with the Barsen'thor, offering information about the possible whereabouts of the First Son.
During the Battle of Corellia, Grann and his fellow General Merion assumed control of Guardian Hold Four. This takeover occurred after Corporal Daresha, secretly a Child of the Emperor, compromised the hold from within. However, their occupation was short-lived, as the then-Barsen'thor and his forces soon launched an assault. Balmorran droids, under the Barsen'thor's command, sabotaged the security systems of Guardian Hold. Simultaneously, a team comprised of Voss commandos and the Barsen'thor himself successfully infiltrated the compound.
When the Barsen'thor arrived, Grann, Merion, and Daresha were all present in the Guardian Hold's conference room. Despite the valiant efforts of the Imperial garrison stationed at Guardian Hold, the Barsen'thor managed to breach the conference room. He then engaged and killed Daresha in a one-on-one fight. Shortly after, Republic forces captured Grann and Merion. Over Merion's objections, Grann decided to cooperate with the Republic. He revealed that the First Son might be hiding in Guardian Hold One alongside the remnants of the Corellian Council. Consequently, the Barsen'thor departed to pursue the First Son, while Grann and Merion were taken into custody.