Holy Roman Emperor (1765–90). He was co‐regent of Austria with his mother Maria Theresa from 1765 and sole ruler from 1780 to 1790. Intelligent, dedicated to the principles of the Enlightenment, and hoping to improve the lives of his subjects, he was nonetheless autocratic and too hasty. Attempts at major reforms brought many parts of the empire close to revolt. His most lasting achievements were the edicts in 1781 granting toleration to Jews and Protestants. He abolished serfdom and curtailed the privileges of the nobles. In German affairs he was outmanoeuvred by Frederick II of Prussia and his alliance with Catherine II (the Great) of Russia led to a disastrous war against the Turks.