The Royal Trust Society Of Belgium (Dutch: Koninklijke Schenking, French: Donation royale) was a donation to the state proposed in a letter by King Leopold II of Belgium on 9 April 1900. In addition some properties were added to the donation in a letter of 15 November 1900. The Belgian government accepted the donation by law on 31 December 1903 (Belgian Monitor of 1 January 1904). When the King handed the Congo Free State over to the Belgian government on 28 November 1907, additional properties were added to the Royal Trust (law of 18 October 1908, published in the Belgian Monitor of 18 October 1908).
The King donated his properties, such as his lands, castles and buildings, to the Belgian nation. Leopold did not want them to be divided amongst his three daughters, each of which was married to a foreign prince. The donation was made on three conditions: the properties would never be sold, they would have to retain their function and appearance, and they would remain at the disposal of the successors to the Belgian throne. Since 1930, the Royal Trust is an autonomous public institution which operates completely independently (Royal decree of 9 April 1930 - Belgian monitor of 29 May 1930).