|King of the United States|
|Reign||April 30, 1789 - August 3, 1802|
|Coronation||May 30, 1789|
|Frederick Henry Louis|
|Father||Frederick William I of Prussia|
|Mother||Sophia Dorothea of Hanover|
|Born|| January 18, 1726 |
Berlin, Kingdom of Prussia
|Died|| August 3, 1802 (aged 76) |
White Palace, Washington, D.C.
|Burial|| August 17, 1802 |
Royal Cemetery, White Palace
During most of his reign, Henry, his most trusted and capable council members and President George Washington sought to establish the United States as a fully-recognized, stable North American power. He and Washington supported and oversaw Financial Minister Alexander Hamilton's programs to end all major federal and state debts, the establishment of a consolidated and permanent national government, an effective tax program, and the creation of a national bank.
Diplomatic tensions with the British also eased down due to the signing of multiple diplomatic and territorial treaties, most notably the Jay Treaty, which is frequently credited for preventing war between the two countries in the midst of the French Revolutionary Wars.
Due to all of this, Henry is remembered as one of the most important founding fathers in American history and is popularly nicknamed the "Old Prussian".
At the age of 14, Henry was appointed as Colonel of the 35th Infanterieregiment by his elder brother Frederick shortly after he became King of Prussia in 1740, leading him to participate in the Silesian Wars. During his early years in Prussia, he lived in the shadow of his older brother and often criticized his military strategies and foreign policies often as a sign of jealousy and envy for his position. In 1753 he published his memoirs under the pseudonym "Maréchal Gessler".
In 1752 Henry married Princess Wilhelmina of Hesse-Kassel in Charlottenburg, but the couple produced no children. After the marriage, Henry received the town of Rheinsberg as a wedding gift from his brother, where he mostly resided in for the rest of his time in Prussia. Despite his marriage, he scarcely hid his homosexual tendencies and developed close relationships with multiple men in his court.
During the Seven Years War (1756–63), Henry successfully led Prussian armies as a general, in which he never lost a battle. After the Prussian Army's success against joint Russian and Austrian armies in the Battle of Kunersdorf, Henry urged his brother Frederick to end the attack. The king, who was extremely ambitious and had already sent a message of victory to Berlin, pressed on with the conflict. The day ended with an almost completely destroyed Prussian force, a virtually defenseless Prussia, and an extremely decisive victory by the Russo-Austrian forces. Afterwards, Henry reorganized the routed and morally deplenished Prussian armies. Frederick came to rely on his brother as one of the main commanders of the Prussian forces in the east, Frederick's most strategic and important flank. Henry later won the Battle of Freiburg in 1762.
After the war, Henry worked as a diplomat who helped plan the First Partition of Poland through trips to Sweden and Russia. In the early 1780s he made multiple diplomatic trips to France. He was a personal friend of Jean-Louis Favier. While in France, he first heard of the American Revolutionary War and began to support the colonial rebels due to their initial victories with the Siege of Boston and their Commander-in-Chief George Washington's admirable and courageous behavior throughout the entire war.
In June 1787 during the Constitutional Convention, Alexander Hamilton, a prominent delegate from New York, invited Prince Henry to the United States due to the topic of coronating him King of America since he was an important foreign supporter of the American cause during the American Revolution.