The National Military Museum came into existence through the amalgamation of the Army Museum in Delft and the Military Aviation Museum in Soest. To ensure the preservation of both collections for the future, the Army and the Air Force made the joint decision to construct a new museum. Furthermore, the Navy Museum in Den Helder, the Marine Corps Museum in Rotterdam, and the Museum of the Royal Military Police in Buren were all brought together under a common foundation. This marked the establishment of the Royal Defense Museums Foundation.