Another cause was Napoleon's formation in July 1806 of the Confederation of the Rhine out of the various German states which constituted the Rhineland and other parts of western Germany. A virtual satellite of the French Empire with Napoleon as its "Protector", the Confederation was intended to act as a buffer state from any future aggressions from Austria, Russia or Prussia against France (a policy that was an heir of the French revolutionary doctrine of maintaining France's "natural frontiers"). The formation of the Confederation was the final nail in the coffin of the moribund Holy Roman Empire and subsequently its last Habsburg emperor, Francis II, changed his title to simply Francis I, Emperor of Austria. Napoleon consolidated the various smaller states of the former Holy Roman Empire which had allied with France into larger electorates, duchies and kingdoms to make the governance of non-Prussian and Austrian Germany more efficient. He also elevated the electors of the two largest Confederation states, his allies Württemberg and Bavaria, to the status of kings.