Cornelis (Kees) Ruizendaal (1909–1944), known in resistance circles by the codename ‘Zwarte Kees’ (Black Kees), formed the operational backbone of the armed resistance in the Achterhoek region. As leader of the Aalten Assault Group (KP-Aalten), he combined his expertise as a soldier and military policeman (marechaussee) with the mission of the National Organisation for Aid to People in Hiding (LO). His death in 1944 was a severe blow to the regional resistance, but led to a regrouping that continued the struggle until the liberation.

Military background and early career

Kees Ruizendaal was born on 17 May 1909 in Maarssen. At a young age, he joined the Royal Netherlands Navy, where he sailed the world’s oceans for six years as a sailor-cook. In 1930, he married Adriana Lucia de Kam (1907–1989).

In November 1937, he joined the Army (8th Infantry Regiment) in Arnhem as a cook. In May 1940, he survived the fierce battle against the German occupiers at the Grebbeberg, a battlefield where many of his fellow servicemen lost their lives. Following the capitulation, he joined the Amsterdam Police as a cook for the police training college. NSB (Dutch Nazi Party) officers were also trained in this building; Kees repeatedly clashed with them, yet nonetheless rose to the rank of head constable. Shortly thereafter, he left Amsterdam for a post in Aalten, where he became a municipal constable and, not long after, post commander.

The transition to active resistance

Ruizendaal quickly became active in the resistance. Thanks to his position, he possessed crucial information, allowing him to warn citizens — and particularly Jewish residents — of approaching danger in good time. As Aalten provided refuge for many people-in-hiding from across the country, he assisted in finding accommodation and providing forged identity cards and ration books.

Despite his position as post commander, he joined the Aalten Assault Group (KP) in mid-1943, which was then led by Jan Wikkerink (‘Ome Jan’) and Willem Wikkerink. Following a betrayal, Ruizendaal had to leave his post and went into hiding in July 1943. Although officially reported as “missing” and ordered to surrender his weapons according to a police report dated 11 September 1943, he withheld them for the resistance. From that moment on, he dedicated himself fully to the KP-Aalten, which operated under his leadership throughout the Achterhoek and collaborated with the KP-Twente.

Fighting for justice

Justice was his primary motivation. Ruizendaal organised and led numerous operations, including raids on distribution offices in Eibergen, Borculo, and Andelst (planned actions in Dinxperlo, Neede, and Winterswijk failed). ‘Zwarte Kees’ knew his way perfectly through all the hamlets of Aalten and the surrounding area; he could stay overnight or sit down for a meal anywhere. While he was constantly on the move, his wife and four children continued to live in their home in the centre of Aalten.

Ruizendaal’s closest KP members included:

• Jaap Allersma: Former professional non-commissioned officer in the artillery and customs officer in Aalten.
• Jan Ket: Former marine and customs officer in Aalten.
• Feitze de Vries (alias ‘Gerrit’): Former marine and customs officer in Aalten.
• Gerrit Wiechert Kleisen (alias ‘Walter’/‘Gijs’): Infantry non-commissioned officer and customs officer.

He also collaborated with Aalten residents Herman Lichtenberg and Gerrit Klein Entink, alias “Willie”.

Fatal firefight in Doesburg

The constant need for weapons led to a tragic event on 20 April 1944. The infiltrator and traitor Willy Markus managed to win the trust of the resistance group and, in cooperation with the occupier, lured them into an ambush in Doesburg. During a failed weapon handover, a firefight broke out with the SS. Ruizendaal hid in a rabbit hutch in a courtyard, where he was ultimately killed.

Although the elimination of Ruizendaal was a heavy blow to the KP-Aalten, ‘Ome Jan’ Wikkerink quickly found successors. He found Gijs van Haaften and Dick Kleisen, and several new people-in-hiding willing to take over command.

In Memoriam

On 4 October 1947, Kees Ruizendaal was reburied with military honours at the Berkenhove General Cemetery in Aalten. He was a man of great courage and a deep sense of justice; his dedication to others ultimately cost him his life. In the late 1980s, a memorial stone for those fallen in the organised resistance was placed on the Market Square in Aalten, next to the Old Helenachurch. One of the seven names on this monument is that of Cornelis Ruizendaal.

Sources

• Information collection Nationaal Onderduikmuseum
• Westmeijer, P. (2021): Zwarte Kees, partizaan in de Achterhoek.
• Derksen, S.C. (1982): Op de drempel van de vrijheid.

Cornelis Ruizendaal (Zwarte Kees), leader of the Aalten Assault Group

Zwarte Kees, partizaan in de Achterhoek | author: Paul Westmeijer