centre because of Dutch neutrality and its strategic location between Britain, Germany and German-occupied Belgium. Many spies who were arrested and executed in Britain were led by German secret agents operating from Rotterdam. MI6 had its main European office on de Boompjes. From there the British coordinated espionage in Germany and occupied Belgium. During World War I, an average of 25,000 Belgian refugees lived in the city, as well as hundreds of German deserters and escaped Allied prisoners of war.

During