The Viking Empire includes a united Scandinavia (including former possessions of Sweden), former Scandinavian colonies in Greenland and Vinland (America), and also assumes successful settlements in North America and parts of the Russian arctic coast.
Most of the lands are quite uninhabitable of course, so this "Empire" could not feed many millions. Nevertheless, it is an impressive landmass on world maps and has a lot of potential for further expansion.
The Habsburg dynasty once ruled Austria-Hungary and the Holy Roman Empire. This scenario assumes a unification of both and also includes dependent Baltic states and parts of Western Francia.
The first map shows the administrative division of the Empire and its neighbouring countries, the second shows the history of the unification, and the third shows the languages spoken within the Habsburg realm.