 Despite being neutral at the start of World War II , Belgium and its colonial possessions found themselves at war after the country was invaded by German forces on 10 May 1940 . After 18 days of fighting in which Belgian forces were pushed back into a small pocket in the north @-@ east of the country , the Belgian military surrendered to the Germans , beginning an occupation that would endure until 1944 . The surrender of 28 May was ordered by King Leopold III without the consultation of his government and sparked a political crisis after the war . Despite the capitulation , many Belgians managed to escape to the United Kingdom where they formed a government and army @-@ in @-@ exile on the Allied side . 
