The Belgian monarchy is a constitutional and hereditary institution, with the monarch titled "King/Queen of the Belgians" serving as head of state and commander-in-chief. Established after Belgium gained independence in 1830, the National Congress appointed Leopold of Saxe-Coburg-Saalfeld as Leopold I, the first King, who took his oath on July 21, 1831—a date now celebrated as a national holiday. Seven monarchs have reigned since, with the current King Philippe ascending in 2013 after his father Albert II's abdication.
Bound by the Constitution, the monarch acts as an arbiter and guardian of national unity, inaugurated in a purely civil swearing-in ceremony. A significant historical figure, King Leopold II, is infamous for establishing the Congo Free State as his personal fiefdom, where widespread atrocities led to its eventual takeover by the Belgian government. His successor, Albert I, notably ruled during World War I and died under mysterious circumstances.