Based on a house treaty, Frederick was to inherit the family's German possessions upon his father's death. After the treaty of Vienna these were no longer in the possession of the family. He instead was made heir to the
Grand Duchy of Luxemburg. In 1816, Frederick relinquished this claim in exchange for land in the Netherlands and the title of
Prince of the Netherlands. As a further compensation he received a yearly amount of 190,000
Dutch guilders. This made him the wealthiest member of the
House of Orange-Nassau. In 1816 Frederick was appointed Grand Master of the
Grand Orient of the Netherlands a function he would hold until his death in 1881. In 1826 Frederick was appointed Commissary-general of the Department of War. In this office, Frederick reorganized the army on a
Prussian model. Frederick founded the
Royal military academy in
Breda and reequipped the army with modern weapons. 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. When the
Belgian Revolution broke out in 1830, Frederick commanded the troops sent to
Brussels to suppress the rebellion there. Frederick led these troops in several days of fighting in Brussels, but could not retake the city. Frederick also took part in the campaign of
his brother's 1831
Ten Days' Campaign in Belgium. When his father abdicated in 1840, Frederick withdrew from public life to his estates at Wassenaar. In 1846 he acquired
Schloss Muskau in Prussia where he completed
Muskau Park, the largest and one of the most famous English gardens in Central Europe, stretching along both sides of the present German–Polish border on the
Lusatian Neisse. The park had been laid out from 1815 onwards at the behest of
Prince Hermann von Pückler-Muskau (1785–1871). In July 2004, Muskau Park was added to the list of
UNESCO World Heritage Sites. Upon the death of his elder brother in 1849, the country was left with a large debt. Frederick managed to pay off a million guilder to Tsar
Nicholas I of Russia, who was brother-in-law to William II. The new
King William III of the Netherlands (Frederick's nephew) did not want to inherit the kingship from his father, but Frederick managed to convince him to take up the position, offering to assist him. William III recalled Frederick and made him Inspector-General of the army. Frederick held that office until 1868, when he resigned because of the lack of support for his plans to modernize the army. Frederick managed to prevent a divorce between King William III and Queen
Sophie of Württemberg by establishing a legal separation. He retired to Muskau Castle, bought by him in 1846, which was remodeled in
Renaissance revival style between 1863 and 1866. ==Marriage==