Augustus II of Saxony, Emperor Leopold I, Frederick I of Prussia, Frederick III of Brandenburg, Frederick the Great, Holy Roman Empire, King in Prussia, King of Poland, The Great Elector Frederick William of Brandenburg
Friedrich I. (July 11, 1657 – February 25, 1713), of the Hohenzollern dynasty, was (as Friedrich III) Prince-Elector of Brandenburg (1688–1713) and Duke of Prussia in personal union (Brandenburg-Prussia). The latter function he upgraded to royalty, becoming the first King in Prussia (1701–1713). From 1707 he was in personal union the sovereign prince of the Principality of Neuchâtel (German: Fürstentum Neuenburg). He was also the paternal grandfather of Friedrich II the Great.
Born in Königsberg, he was the third son of Friedrich Wilhelm, the Great Elector of Brandenburg by his father’s first marriage to Louise Henriette of Orange-Nassau, eldest daughter of Frederick Henry, Prince of Orange and Amalia of Solms-Braunfels. His maternal cousin was King William III of England. Upon the death of his father on April 29, 1688, Friedrich became Elector Friedrich III of Brandenburg and Duke of Prussia. Right after ascending the throne Friedrich founded a new city southerly adjacent to Dorotheenstadt and named it after himself, the Friedrichstadt.
The Hohenzollern state was then known as Brandenburg-Prussia. The family’s main possessions were the Margraviate of Brandenburg within the Holy Roman Empire and the Duchy of Prussia outside of the Empire, ruled as a personal union. Originally the dukes of Prussia held the fief as vassals of the King of Poland, until the Treaties of Labiau (1656) and Bromberg (1657), with which Friedrich Wilhelm, the Great Elector, claimed full sovereignty from the Polish Crown. Originally the province of Royal Prussia was part of the Kingdom of Poland, the Kings of Poland titled themselves Kings of Prussia until 1742.
Although Friedrich was the Margrave and Prince-Elector of Brandenburg and the Duke of Prussia, Friedrich desired the more prestigious title of king. However, according to Germanic law at that time, no kingdoms could exist within the Holy Roman Empire, with the exception of the Kingdom of Bohemia which was in personal union with the Holy Roman Emperor.
In the Crown Treaty of November 16, 1700, Friedrich persuaded Leopold I, Holy Roman Emperor, to allow Prussia to be elevated to a kingdom. This agreement was ostensibly given in exchange for an alliance against King Louis XIV of France and Navarre in the War of the Spanish Succession and the provision of 8,000 Prussian troops to Leopold’s service.
Friedrich argued that Prussia had never been part of the Holy Roman Empire, and he ruled over it with full sovereignty. Therefore, he said, there was no legal or political barrier to letting him rule it as a kingdom.
Friedrich III of Brandenburg crowned himself on January 18, 1701 in Königsberg, becoming King Friedrich I in Prussia. Although he did this with the Emperor’s consent, and also with formal acknowledgement from Augustus II the Strong, Elector of Saxony, who also held the title of King of Poland, the Polish-Lithuanian Diet (Sejm) raised objections, and viewed the coronation as illegal.
In fact, according to the terms of the Treaty of Wehlau and Bromberg, the House of Hohenzollern’s sovereignty over the Duchy of Prussia was not absolute but contingent on the continuation of the male line (in the absence of which the duchy would revert to the Polish crown). Therefore, out of deference to the region’s historic ties to the Polish crown, Friedrich made the symbolic concession of calling himself “King in Prussia” instead of “King of Prussia”.
His royalty was, in any case, limited to Prussia and did not reduce the rights of the Emperor in the portions of his domains that were still part of the Holy Roman Empire. In other words, while he was a king in Prussia, he was still only an elector under the suzerainty of the Holy Roman Emperor in Brandenburg. Legally, the Hohenzollern state was still a personal union between Brandenburg and Prussia.
The title “King in Prussia” reflected that Friedrich was only sovereign over his former duchy. In Brandenburg and the other Hohenzollern domains within the borders of the empire, he was legally still an elector under the ultimate overlordship of the emperor.
However, this was legal fiction. By this time the emperor’s authority had become purely nominal. The rulers of the empire’s member states acted largely as the rulers of sovereign states, and only acknowledged the emperor’s suzerainty in a formal way. Hence, even though Brandenburg was still legally part of the empire and ruled in personal union with Prussia, Brandenburg soon became to be treated as a de facto part of Prussia.
Throughout the 18th century, the Hohenzollerns increased their power. They were victorious over the Austrian Habsburg Monarchy in the three Silesian Wars, greatly increasing their power through the acquisition of Silesia. King Friedrich II adopted the title King of Prussia in 1772, the same year he annexed most of Royal Prussia in the First Partition of Poland.
The kings of Prussia continued to be Electors of Brandenburg until the empire’s dissolution in 1806. Brandenburg was then made a Prussian province, and Berlin officially became the kingdom’s capital. In 1871 the Hohenzollerns became German Emperors of the new unified German Empire which lasted until the end of World War I.