WWI (1914 - 1918) military war machines were called tanks, because they were originally disguised to resemble water tanks. Tanks with cannons were called male tanks and tanks with machine guns were called female tanks.
'Little Willie' was
developed in 1915 by British
scientists and inventors, and it was
the first World War 1 tank. The
British produced over 2,600 tanks
during the war, but by the end
of the war British Tank Corps had
only 8 tanks left.