Despite being neutral at the start of World War II, on 10 May 1940 Belgium and her colonial possessions found themselves at war after an invasion of the country by German forces. Following 18 days of fighting, the Belgian army surrendered to German forces beginning an occupation of the country that would endure until its liberation by Allied forces in late 1944. Amongst those that surrendered was King Leopold III, whose decision sparked a political crisis after the war. Nevertheless, after the surrender, many Belgians managed to escape to the United Kingdom where they formed a government and army-in-exile to continue fighting.