When Napoleon returned from Elba, during the Hundred Days the prince was given command of a detachment of Wellington's army which was posted in a fall back position near Braine-le-Comte should the battle taking place at Waterloo be lost.

Based on a house treaty, Frederick was to inherit the family's German possessions upon his father's death.

[1] With the money he bought a large estate in Germany, which made him the largest land owner from the Netherlands.

[1] Aged 18, Frederick was made a major-general by his father and given nominal command of the Dutch-Belgian 1st Division (lt.-gen. Stedman) that was tasked with guarding Wellington's escape route to the sea in case things would have gone awry for the Anglo-Dutch army at the Battle of Waterloo.

In 1829 Frederick was a candidate for the Greek throne, but he declined because he did not want to be king of a country whose language and traditions were foreign to him.

Frederick managed to pay off a million guilder to Tsar Nicholas I of Russia, who was brother-in-law to William II.

Frederick managed to prevent a divorce between King William III and Queen Sophie of Württemberg by establishing a legal separation.