The royal greenhouses at Laeken include a number of buildings spreading over approximately 1.5 ha (4 acres). An orangery was built here as early as 1817 but it was King Leopold II who inspired construction of the many glass houses now at the site. Anxious to imitate the success of the Crystal Palace in London, Leopold commissioned his architect Alphonse Balat to build the royal greenhouses in the 1870s to house plants from around the world as well as to serve as royal reception centers.
Historical Dictionary of Brussels. Paul F. State.