VUB CASE: From Neutral Constraint to Sovereign Control: Belgium's Immigration Policy Transformation (1839–1940)

 1. Belgium's Awkward Origin Story: Neutrality as Identity

To understand Belgium's immigration policy, one must begin not with migration law but with geopolitics, with Belgium's rather awkward birth. It all started when the Belgians got sick of the Dutch and wanted independence. Its independence came at a price: permanent neutrality, imposed by the Big 5 of that time: Britain, France, Prussia, Austria, and Russia. This was formalised in the Treaty of London of 1839, Article 7: "Belgium shall form an independent and perpetually neutral State." In short: little Belgium should mind its little business and stay out of any conflicts, conformably to neutrality's main obligations: abstention and impartiality.

Now, being forced into neutrality by five larger countries is not exactly the most heroic origin story. But that neutrality ended up shaping Belgium’s political culture, its foreign policy, and eventually its treatment of foreigners. In practice, your nationality barely mattered for everyday life, as long as you could support yourself and stay out of trouble. The Belgian liberal regime took pride in the protection it offered to those persecuted for their convictions. Political exiles were welcomed as long as they remained politically quiet. 

(Photographed by Andrew Ruppenstein, May 15, 2023; source here)

After being expelled from France, Karl Marx lived in Brussels from 1845 to 1848. Belgium welcomed him in the spirit of liberal openness. Fun fact: he wrote the Communist Manifesto there. His visit lasted until revolutions began spreading across Europe in 1848. When the Belgian authorities grew nervous about radical foreigners stirring things up, they expelled him too.

The legal basis for this liberal openness could be found in two elements of Belgian law. Article 128 of the Constitution of 1831 established that anyone on Belgian soil, whether foreign or not, was entitled to equal treatment under the law. The parliament alone could create exceptions to that rule. A rule would not be a rule without an exception, and the Aliens Act of 22 September 1835 created one. It gave the government the power to expel foreigners who disturbed public order or had been convicted of crimes abroad. But that power was still limited: expelling a settled foreigner required a formal Royal Decree. These protections remained in place in the revised Aliens Act of 12 February 1897.

2. Germany Enters the Chat: War, Exile, and Emergency Control

On 4 August 1914, Germany invaded Belgium. Germany had its eyes on France and Belgium happened to be in the way. When Germany requested passage through Belgian territory, little Belgium said no. Germany, seemingly determined to become the ultimate villain of that time, did not take no for an answer. 

(map [in Dutch] of the front and German occupation; source: WO1 at site)

The Belgian government, in exile in Le Havre, introduced two key legal instruments. The decree-law of 11 October 1916 allowed the government to detain foreigners based solely on their nationality, targeting enemy nationals. For the first time, a person’s national origin became the basis for detention without judicial involvement. The decree-law of 12 October 1918 went further by giving government the power to control any foreigner in Belgium, not just enemy nationals.

(The Decree-Law of 12 October 1918, excerpt; source: Pasinomie)

3. The Peace That Wasn't: How Versailles Rewrote the Rules on Migration

The Treaty of Versailles of 1919 formally ended the war, although calling it a peace treaty was optimistic. For Belgium, it ended the regime of permanent neutrality, opened the way for accession to the League of Nations, and transferred the territories of Eupen Malmedy to Belgian sovereignty. Together, these changes strengthened the idea of Belgium as a fully sovereign state, a shift that would soon influence how it regulated foreigners.

In the interwar years, Belgium’s migration policy became increasingly restrictive. The Aliens Act of 1897 technically stayed in place, but in practice the authorities found ways to work around it. Because the 1897 law prohibited the expulsion of resident foreigners, repatriation became a convenient administrative workaround. Visa requirements were introduced in 1919 and the Royal Decree of 15 December 1930 made work permits mandatory for foreign workers. From 1933 onward, additional decrees tightened residency conditions and expanded the state’s ability to remove foreigners. 

At the same time, Belgium made bilateral labour agreements with Italy in 1922 and with Poland in 1924. These agreements formalised the recruitment of foreign labour for Belgian industry, particularly the coal sector.  

In 1929, Belgium reorganised its internal security administration, the Sûreté publique. This created the Police des Étrangers, a separate service responsible for the surveillance, documentation, and possible removal of foreigners. 

4. The Interwar Machine in Motion

The Great Depression arrived in 1929, as if things needed to be more depressing. The economic crisis quickly pushed Belgium toward a more restrictive approach. Throughout the early 1930s, the authorities expanded the grounds for expulsion and tightened the rules on who was allowed to stay. 

(image: King Leopold III of the Belgians behind his desk; source: Nationaal Archief (NL))

The idea of the “undesirable alien” also emerged in these years. It was an informal label for foreigners seen as a risk to public order, national security, or the economy. It wouldn’t become an official legal category until 1939. 

Italians benefited from the 1922 agreement, which gave them a relatively secure position in the Belgian labour market. The Poles, on the other hand, were welcomed as cheap labour for the coal mines but had a far more vulnerable position. 

The treatment of Polish workers shows how the system really worked. The law technically protected them from expulsion. Yet they were excluded from unemployment benefits, and the Police des Étrangers often used “voluntary” repatriation to push them out of the country. 

Germans in Belgium were increasingly treated as a security risk especially political activists and anyone suspected of ties to the new regime. And when Jewish refugees began arriving later in the decade, the country’s doors were already closing. The state that once prided itself on offering refuge now turned people away. 

On the eve of the war, the government used the broad special powers granted to it by parliament to issue the special powers decree of 28 September 1939. This gave the government complete control over the presence of all foreigners, stripping away almost all remaining legal protections. It created a generalised category of foreigners who could be removed with an administrative decision alone. The apparatus was now fully in place.

(Decree-law of 28 September 1939, excerpt; source: Pasinomie)

5. Two Sequels Nobody Asked For: Neutrality Returns, Germany Follows

While all of this was unfolding, King Leopold III had what he considered a great idea: Belgium would return to neutrality. In 1936, he announced exactly that. The declaration invites direct comparison with 1839. Belgium’s original neutrality came with a collective guarantee from five Great Powers, each with an interest in keeping the country out of anyone else’s hands. Versailles changed that. After 1918, Belgium joined the League of Nations and aligned itself with France and Britain, which was an active foreign policy posture that had nothing to do with neutrality. 

And unlike in 1839, Belgium was no longer a passive state. The Police des Étrangers, the interwar registration systems, the individual dossiers, and the expanding expulsion system were all firmly in place. You cannot return to passive openness once you have built an active control state. Germany invaded again on 10 May 1940. Apparently once was not enough. The control apparatus did not disappear; it was simply taken over by the occupier. Belgian administrative institutions, including the Police des Étrangers, played an active role in the persecution of Jews during the occupation.

Aichat Okueva

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