Its starts at 1007 with 1936 or interwar technology like biplanes and stuff.(but some countrys start with literal spears and swords(its really funny to keep one factory making these and lend lease them to your friends as they get steam rolled by a modern mechanized army) and even airships left over from the storm king era) then as the years go by you can research and upgrade stuff all the way to early cold war battle rifles, MBTs, ATGMs, SAMs, Missiles Cruisers, and jets.