"mushroom growths like the Hapsburgs and the Romanoffs can never reach"

The Habsburgs were a powerful royal German family whose members ruled as Holy Roman Emperors almost uninterruptedly from 1440 to 1806. Through a series of royal intermarriages, they gained a great deal of power and influence in Europe, including controlling the Spanish Empire at the height of its global reach. Later, they would rule the Austrian and Austro-Hungarian Empires, until the latter's dissolution in 1918.

Habsburg Dominions in 1547
Public DomainHabsburg Dominions in 1547 - Credit: The Cambridge Modern History Atlas

The Romanoffs (Romanovs) were a Russian imperial dynasty that ruled between 1613 and 1917 (when they were removed and executed during the February Revolution).