The Cardinal de Richelieu was often known by the title of the King's "Chief Minister". As a result, he is sometimes said to be the world's first Prime Minister. He sought to consolidate royal power and crush domestic factions. By restraining the power of the nobility, he transformed France into a strongly centralized state. His chief foreign policy objective was to check the power of the Austro-Spanish Habsburg dynasty; although a Roman Catholic cardinal, he did not hesitate to make alliances with Protestant rulers. With these alliances, he tried to achieve this goal. His tenure was marked by the Thirty Years' War that engulfed Europe.