Frederick William was born in Potsdam on August 3rd, 1770, the son of King Frederick William II and Frederica Louisa of Hesse-Darmstadt.
He married in 1793 Louisa von Mecklemburg-Strelitz (with whom he had nine children) then, in 1824, Augusta von Harrach.
He became King of Prussia on November 16th, 1797.
He passed away in Berlin on June 7th, 1840. His eldest son succeeded him as Frederick William IV.Ludwig van Beethoven dedicated to him his ninth symphony in 1826.