The large-scale General Headquarters (GHQ) exercise known as “Spartan,” held in the south of England during March 1943, was a significant event in the history of the Canadian Army in the Second World War. The purpose of “Spartan” was to test the army in the dual tasks of breaking out of an established bridgehead and making the transition to open warfare. As a direct result of shortcomings on the exercise, three Canadian generals lost their commands. Of greatest significance was the eventual relief of General A.G.L. McNaughton as commander of the First Canadian Army in November 1943. During and after “Spartan” the Chief of the Imperial General Staff (CIGS), General Sir Francis Alan Brooke, and the Commander-in-Chief of Home Forces, General Sir Bernard Paget, claimed that McNaughton’s performance proved his incapacity to lead First Canadian Army in the field. In consequence, Brooke and Paget orchestrated his removal and Canadian military historians have generally supported their assessment. However, the considerable criticism directed at McNaughton resulting from “Spartan” has suffered from oversimplification. This article will review McNaughton’s performance during the exercise and assess its role in his relief.