Countries that were annexed by, or at war with, Axis Powers before the World War II
Austria (annexed to Germany, "Anschluss", March 13th, 1938)
Ethiopia (annexed by Italy in 1936, after the Abyssinia crisis, independence restored in 1941)
Republic of China (at war with Japan since 1931)
It's here, and I assume it's from 1931-1945 because Japan is still far from its peak when WW2 broke out in 1939, and it maybe that the authors of the website pay more attention to Europe and Pacific.
However it's strange to exclude China from the "Allies list", I think China did have treatment with the Allies.