History of Holland and Belgium during World War I
Invasion of Belgium by Nazi Germany started on May 10, 1940 under the operational plan Fall Gelb and formed part of the greater Battle of France together with invasions of the Netherlands and Luxembourg. The Belgians put up a short lived resistance and it took three weeks of fighting before the country was subdued. The Netherlands hoped to stay neutral when World War II broke out in 1939 but this failed to come true when Nazi Germany invaded the Netherlands in May 1940. Dutch resistance grew in the course of the five years of the occupation.