Although the so-called Emperor's Fist Darth Vader was considered a military commander and acted as de facto Commander-in-Chief of the Imperial Armed Forces in that he had authority that came directly from Galactic Emperor Sheev Palpatine himself, Vader lacked any formal title other than "Lord." Instead, the mundane responsibilities of the military-industrial complex were not among the attributes of Vader. Those responsibilities fell to the Supreme Commander, who was briefed daily by the Joint Chiefs, created the agenda of the armed forces to fulfill the Emperor's galactic strategy, and managed Imperial High Command. The individuals who achieved the rank of Supreme Commander reportedly did not retain it for long, as the Emperor promoted infighting and competitiveness among the senior officers, and shifted assignments and responsibilities frequently.
After the Battle of Yavin, General Cassio Tagge was simultaneously promoted to the military rank of Grand General and elevated by Emperor Palpatine to the office of Supreme Commander, thus granting him authority over the briefly demoted Lord Vader and putting him in charge of overseeing the war effort against the Rebellion and the cracking down of criminal elements like the Crymorah Syndicate and the Son-tuul Pride. General Tagge held the position until he was stripped of his new rank by Emperor Palpatine and subsequently killed by the intolerant Lord Vader for his multiple blunders during the War on Shu-Torun and his misplaced trust in the rogue Doctor Cylo.
- Dawn of Rebellion