Belgium opened an embassy in Switzerland in 1840, while Switzerland opened its embassy in Brussels in 1918. These were later followed by consulates general in Geneva and Antwerp, as well as Belgian consulates in various Swiss cities.
The First World War strengthened ties between the Belgian and Swiss populations. When Belgian neutrality was disregarded by the German troops, this triggered fierce criticism, especially in French-speaking Switzerland. Switzerland took in 2,000 hospitalised Belgian children and interned 4,500 wounded officers and soldiers, as well as 6,000 refugees, including the industrialist Ernest Solvay and the poet Emile Verhaeren.
The Belgian royal family has always maintained good relations with Switzerland. King Albert I was a regular visitor to the country, while Leopold III lived with his family in Switzerland from 1945 to 1950. When King Leopold III abdicated in 1959, his son King Baudouin I continued to maintain good relations with Switzerland, and was received on a state visit here in 1989. Eleven years later King Albert II paid a state visit to Switzerland on 21 and 22 November 2000. His eldest son, Philippe, who was enthroned as King of the Belgians on 21 July 2013, continues the royal family tradition and regularly spends holidays in Switzerland.
Belgium, historical Dictionary of switzerland (de, fr, it)