In the ensuing political vacuum a triumvirate of former Orangist regents, led by Gijsbert Karel van Hogendorp, invited the former Hereditary Prince (the old Stadtholder had died in 1806) to assume power as "Sovereign Prince." William VI of Orange landed in Scheveningen on 30 November 1813. He duly established control in the Netherlands and was offered the crown of the combined area of the former 17 provinces of the Netherlands (modern Belgium and the Netherlands) by the Allies in the secret London Protocol (also known as the Eight Articles of London) of 21 June 1814, which he accepted exactly one month later. On 16 March 1815, the United Kingdom of the Netherlands was proclaimed.