General Williams served as a Systems Alliance commander of the garrison on Shanxi when the First Contact War broke out. After humans were caught activating the mass relay known as Relay 314, an Alliance expeditionary fleet was attacked and almost completely destroyed by a turian patrol fleet. After several small skirmishes, the turians broke through to Shanxi, the closest human colony to the Shanxi-Theta relay, and began a brutal siege campaign utilizing orbital bombardment.
Cut off from reinforcements, Williams commanded a desperate guerrilla campaign from Shanxi's surface. However, the turians' brutal and efficient tactics made it impossible for the human forces to make any headway. Entire city blocks were destroyed by the turians just to exterminate small marine fire teams. Finally, Williams realized that the only way to save what was left of Shanxi's population was to surrender to the turians.
Shortly thereafter, Shanxi was liberated by the Alliance Second Fleet, but before a full-scale war could break out, the Citadel Council intervened and brokered a truce between humanity and the turians. General Williams went down in history as the only human commander to surrender to an alien force, and he fell into disgrace. While no official charges were brought up against him, Williams was drummed out of the military, and he eventually ended up working construction out in the colonies.
Unfortunately, General Williams' disgrace also stained the name of his family. His son also enlisted in the Alliance Navy, but because of his father's reputation, he never rose above the rank of serviceman third class. Williams' granddaughter, Ashley Williams, was kept from obtaining a posting in the Alliance Fleet. Instead, she was relegated to ground force garrisons on human colonies. There have been attempts by some Alliance historians to exonerate General Williams, but these efforts have proven fruitless thus far.