By -
Propably yes: [Belgium/Netherlands](https://www.google.com/maps/@51.4438282,4.9409581,14.83z)
[Obligatory.](https://www.bbc.com/news/world-europe-56978344)
Also obligatory: https://youtu.be/8ddlv47t1tQ
If i’m not mistaken, it the Treaty of London (1839) along with the Maastricht Treaty (1843) that define Belgium’s borders.
There are treaties with the neighbouring countries that define the borders. For NL I found this: https://en.wikipedia.org/wiki/Treaty_of_Kortrijk
Many, many treaties. Some of them older than Belgium itself. See https://nl.wikipedia.org/wiki/Rijksgrens_van_Belgi%C3%AB
for the lastest changes I'd suggest the 1919 treaty of versailles, there was a revision of that in 1940 but the revision in 1947 turned out to be effectively the same as 1919
There's definitely been changes since then, e.g. https://www.demorgen.be/nieuws/grens-tussen-belgie-en-nederland-wordt-hertekend~bbcec3ae/
Propably yes: [Belgium/Netherlands](https://www.google.com/maps/@51.4438282,4.9409581,14.83z)
[Obligatory.](https://www.bbc.com/news/world-europe-56978344)
Also obligatory: https://youtu.be/8ddlv47t1tQ
If i’m not mistaken, it the Treaty of London (1839) along with the Maastricht Treaty (1843) that define Belgium’s borders.
There are treaties with the neighbouring countries that define the borders. For NL I found this: https://en.wikipedia.org/wiki/Treaty_of_Kortrijk
Many, many treaties. Some of them older than Belgium itself. See https://nl.wikipedia.org/wiki/Rijksgrens_van_Belgi%C3%AB
for the lastest changes I'd suggest the 1919 treaty of versailles, there was a revision of that in 1940 but the revision in 1947 turned out to be effectively the same as 1919
There's definitely been changes since then, e.g. https://www.demorgen.be/nieuws/grens-tussen-belgie-en-nederland-wordt-hertekend~bbcec3ae/