June 9, 1815, after 400 years of domination by various European nations, Luxembourg was made a grand duchy by the Congress of Vienna. It was granted political autonomy in 1838 under King William I of the Netherlands, who also was the Grand Duke of Luxembourg. The country considers 1835 to be its year of independence. In 1867, Luxembourg was recognized as independent and guaranteed perpetual neutrality. However, until 1890 king William III of the Netherlands was also Grand Duke of Luxembourg. In 1890 there were different successors in the Netherlands and Luxembourg because a woman could not be Grand Duke.
After being occupied by Germany in World War I and by Nazi Germany in World War II, however, Luxembourg abandoned neutrality and became a charter member of the North Atlantic Treaty Organization (NATO) in 1949.
The present sovereign, Grand Duke Jean, succeeded his mother, Grand Duchess Charlotte, on November 12, 1964. Grand Duke Jean's eldest son, Prince Henri, was appointed "Lieutenant Représentant" (Hereditary Grand Duke) on March 4, 1998. On December 24, 1999, Prime Minister Juncker announced Grand Duke Jean's decision to abdicate the throne in October 7, 2000, in favor of Prince Henri who assumed the title and constitutional duties of Grand Duke.