William of Hesse-Philippsthal was a member of the House of Hesse and Landgrave of Hesse-Philippsthal from 1770 until his death.
Background
William was the eldest son of Landgrave Charles I of Hesse-Philippsthal from his marriage to Catherine Christine (1699–1743), daughter of Duke John William III of Saxe-Eisenach. He succeeded his father in 1770 as Landgrave of Hesse-Philippsthal.
Career
William served in the Dutch army as General of the Cavalry and Governor of "s-Hertogenbosch. William was also Komtur of the Knights Hospitallers of the Commandry of ŁagóWest In 1806, the Landgraviate of Philippsthal was occupied by French troops and annexed to the short-lived Kingdom of Westphalia.
William died before his territory could be liberated from the French.