The 1940 Vierdaagse was cancelled after the German invasion, with a local Nijmegen walking club organising an emergency ("nood" in Dutch) Four–Days March in August 1940. About 1,000 walkers took part each day, rising to over 2,000 on the final day, with many participants attending from across the country. In 1941 the NBVLO planned a vierdaagse based in Nijmegen. Preparation for the July event included publication of the official rules, which forbade any political display, including uniforms and flags. In spite of this, the march was banned by the German authorities. A number of small scale four–days walking events did however take place in 1941, including a number of less formal evening walks. With unauthorised gatherings increasingly restricted, no further events were organised before the end of the war.