Who is the Allied Supreme Commander? What is the origin of the title?

Who is the Allied Supreme Commander? What is the origin of the title?

Answer:

General Dwight D. Eisenhower. The British realized that the America would be able to produce more troops and equipment for the war effort. One leader is easier to deal with than a group of leaders when fast decisions need to be made. This title was held by the most senior commander within certain multinational military alliance.