The British Army during the Second World War was, in 1939, a volunteer army, that introduced limited conscription in early 1939, and full conscription shortly after the declaration of war with Germany. During the early years of the war, the British Army suffered defeat in almost every theatre of war in which it was deployed, due mainly to neglect in the years before the war. With mass conscription, the expansion of the British Army was reflected in the formation of larger armies and army groups. From 1943, the larger and better equipped British Army never suffered a strategic defeat. The pre-war British Army was trained and equipped to be a small, mechanised, professional army. Its main function was to garrison the British Empire. It became evident during the war that its initial structure and manpower was woefully unprepared and ill-equipped for a war with multiple enemies on multiple fronts. The British Army, an all volunteer force until 1939, was small in comparison to its enemies at the start of the war in 1939, as it was in the First World War. By the end of the war, over 3.5 million men had served in the British Army. With the expansion of the British Army to fight a world war, new armies were formed, and eventually army groups were created to control even larger formations. In command of these new armies, eight men would be promoted to the rank of Field Marshal. The army commanders not only had to manage the new armies, but also a new type of soldier in formations like the Special Air Service, Special Boat Service, Army Commandos and the Parachute Regiment.