In 1907, during the Second Hague Peace Conference, the first stone was laid for the construction of the Peace Palace. The design of the Peace Palace came from French architect Louis Cordonnier, who won the international competition with a total of 216 entries. During construction, the design was modified by Dutch architect and site manager Johan van der Steur. The landscape around the Peace Palace was designed by British garden architect Thomas Mawson. After a six-year construction period, the Peace Palace was officially opened on 28 August 1913.