What Families Found After the Dutch Collaboration Archive Opened

Last year, we wrote about a major change for anyone researching Dutch families during the Second World War: records from the Centraal Archief Bijzondere Rechtspleging (CABR) were becoming far easier to search.

The archive contains files connected to hundreds of thousands of people investigated after the German occupation of the Netherlands. When the public names index appeared on 2 January 2025, researchers could suddenly search for relatives whose wartime histories may previously have been difficult to trace. You can read our earlier article about the opening of the CABR.

Since then, people have started following those names into the files themselves. Some found confirmation of stories that had circulated in their families for decades, while others discovered that a name in the CABR could have a much more complicated explanation.

When a familiar family story became more complicated

When Peter Baas searched the newly released index, he found the name of his father, Ludolf Baas. Ludolf was known to him as a resistance fighter, yet his name appeared in an archive associated with postwar investigations into suspected collaboration.

The records explained why. According to reporting by the Associated Press, Ludolf had joined an organisation at the age of nineteen that later became connected with the Dutch Nazi movement. He subsequently became active in the resistance and helped carry microfilm documenting Nazi atrocities across enemy lines.

His case shows why a name in the CABR index needs context. The file behind it may confirm a family story, add a missing chapter, or show that a person's wartime history was more complicated than later generations understood.

Why a name in the index needs context

This became clear soon after the database opened. The National Archives stressed that appearing in the CABR does not prove that someone collaborated with the German occupiers, because the archive was created from the postwar system of bijzondere rechtspleging, or special justice, and includes people who were investigated as well as others connected to those investigations.

Researchers soon encountered resistance members, witnesses and victims among the names. Jewish people also appeared for several reasons, including as witnesses, as people connected to other investigations, or because of complicated postwar administrative procedures.

For genealogists, the search result should therefore be treated as a lead into the archive. The reason a person appears only becomes clear after consulting the underlying file and placing it alongside other evidence.

The files can also reveal the stories of victims

As more of the archive has been digitized, researchers have gained the ability to search inside the documents themselves. A file created around one investigated person may contain witness statements, police reports and correspondence mentioning resistance members, Jewish victims, neighbours, family members and others connected to arrests, raids or betrayals.

This makes the CABR useful for a much wider range of family-history questions. Someone who was never investigated may still appear in testimony inside another person's dossier, and the National Archives now points researchers toward searches for victims, resistance participants and specific wartime events as well as suspected collaborators.

For descendants, this can fill gaps that were difficult to address through conventional civil or population records alone. A wartime event that left little documentation elsewhere may have been described in detail during a postwar investigation.

When family history becomes more personal

The opening of the archive has also brought old family questions back to the surface. Collaboration remained a sensitive subject in many Dutch families for decades, and some descendants grew up knowing very little about what a parent or grandparent had done during the occupation.

ARQ Kenniscentrum Oorlog, Vervolging en Geweld has described both curiosity and anxiety among descendants using the archive. Greater access can provide long-awaited answers, but those answers may also challenge stories that have been repeated within a family for generations.

That gives CABR research a different character from many other genealogical sources. An address, occupation or marriage date usually adds another detail to a family tree, while an interrogation or witness statement can change how a family understands a relative's choices and experiences during the war.

Access has expanded since 2025

The archive has also become easier to consult since the first names were released. The original plan was to make the digitized CABR available online, but privacy concerns led to a more limited form of access when the public names index launched in January 2025.

From 1 July 2025, researchers could search digitized CABR records on secure computers at the National Archives in The Hague. From February 2026, digital access expanded to additional locations across the Netherlands, including the NIOD and regional archives.

Digitization is still continuing, so some files are available digitally while others still need to be consulted in their original form. Researchers can begin with Oorlog voor de Rechter to search the names index and then use the National Archives CABR research guide to see how a relevant file can be accessed.

What the first searches have taught us

The first period of wider access has shown how carefully these records need to be read. A resistance fighter may appear because of an earlier investigation, a victim may surface inside someone else's file, and a family story may prove broadly correct while still leaving out an important chapter.

The CABR can answer questions that have remained unresolved for decades, but those answers usually emerge from the documents behind the search result rather than from the name itself. For family historians, that makes the index especially useful as a starting point for deeper research into what happened during and immediately after the occupation.