Vehicles used between 1939 and 1945 fall into the World War II category. Even though this era spans the shortest number of years, it is by far the most popular for armor modelers due to the enormous range of vehicles used and the vast improvements in armor technology. During the early part of the war, most armored vehicles were smaller, less heavily armored, and lightly armed. Major tank engagements early on convinced governments on all sides of the need for more survivable and deadlier vehicles. This means that there is a large variety of different subjects which were designed to fulfil different roles under different doctrines.