Friedrich Freiherr von der Trenck (16 February 1726 – 25 July 1794) was a Prussian officer, adventurer, and author.
The coat of arms of the Trenck family depicts in red the head of a silver bull with golden tongue and golden horns. Below there are two golden stars. The German word for "bull" is Stier which explains why the family was also known as Stier.
Von der Trenck was born in Haldensleben, which is north of Magdeburg, Saxony-Anhalt, Prussia, on 16 February 1727. His parents were Major-General Baron Christopher Ehrenreich von der Trenck and Marie Charlotte von Derschau. His father was transferred to Königsberg in 1729. Friedrich's grandfather was Albrecht Frederick von Derschau, who was President of the Royal Law Court in Königsberg.
Documents show that Friedrich was a law student in 1741 at the University of Königsberg. In November 1742 he became a cadet in Frederick the Great's garde de corps and six weeks later was given the commission of Cornet. In August 1744 during the Silesian Wars Friedrich was sent to Silesia and became an orderly officer of Frederick the Great. Unfortunately for Friedrich, his first cousin Baron Franz von der Trenck, who was on the side of Austria, nearly captured Frederick the Great and returned his cousin's horses that had been taken by an Austrian officer. Rumors spread that Friedrich was an Austrian spy and after it was learned that he was Franz von Trenck's sole heir, the rumors were impossible to silence. Friedrich was imprisoned one year later, in 1745, at Glatz under the guard of Heinrich August de la Motte Fouqué. The king ordered that Friedrich had to sit on his own gravestone.
In 1746, von der Trenck escaped from the fortress of Glatz (Kłodzko). Then, in 1749, he obtained an employment as Rittmeister of an imperial cuirassier regiment in Hungary. He traveled to Russia where he, or so he claimed, became gentleman of the bed chamber in the court of Tsarina Elizabeth of Russia. He fell in love with a married woman, whose name he never revealed.