- Frederick William I (German: Friedrich Wilhelm I.; 14 August 1688 – 31 May 1740), known as the Soldier King (German: Soldatenkönig), was King in Prussia and Elector of Brandenburg from 1713 until his death in 1740, as well as Prince of Neuchâtel. Frederick William instituted major military reforms, and expanded the army to new limits. He also made efforts to reduce crime and corruption in his state and centralized his authority during his 27 years reign, cementing Prussia as a regional power. His other notable decisions would be the selling of Prussian overseas colonies and the foundation of the Canton system, as well as the conquest of the port of Stettin. He was succeeded by his son, Frederick the Great.
- Frederick William ordered Fritz to undergo a minimal education, live a simple Protestant lifestyle, and focus on the Army and statesmanship as he had. However, the intellectual Fritz was more interested in music, books and French culture, which were forbidden by his father as decadent and unmanly.
- At age 16, Frederick seems to have embarked upon a youthful affair with Peter Karl Christoph von Keith, a 17-year-old page of his father.
- After the prince [Frederick II, better known as Frederick the Great] attempted to flee to England with his tutor, Hans Hermann von Katte, the enraged King [Frederick William I of Prussia] had Katte beheaded before the eyes of the prince, who himself was court-martialled.
- Frederick William had his son married to Princess Elisabeth Christine of Brunswick-Wolfenbüttel-Bevern, whom Frederick despised, but then grudgingly allowed him to indulge in his musical and literary interests again.