Page "Confederation of the Rhine" Paragraph 4

Instead of a monarchical head of state, as the Holy Roman Emperor had been, its highest office was held by Karl Theodor von Dalberg, the former Arch Chancellor, who now bore the title of a Prince-Primate of the confederation.

As such, he was President of the College of Kings and presided over the Diet of the Confederation, designed to be a parliament-like body though it never actually assembled.

The President of the Council of the Princes was the Prince of Nassau-Usingen.