Roughly, these boundaries are pretty old. Some date back to the
middle ages. Some are fairly new (North and South Holland weren't
divided until about two centuries ago), and some are very new (the
province of Flevoland came into existence about fifteen years ago, I
can't remember when, but it is all land reclaimed from the sea -
except two small islands, that formerly belonged to North Holland and
Overijssel).

The border between North Brabant and Antwerp roughly follows the
boundary between the Republic and the Austrian/Spanish Netherlands
(I'm leaving out some minor changes here, for instance at Huybergen).

Of course, there were many small boundary changes, and a few big
ones, as well. But there were never such rigorous boundary changes
as, say, in Wales and England acc. to the Local Government Act of
1972 (now, it has all changed again...).

Peter S.

--- In BoundaryPoint@y..., Anton Sherwood <bronto@p...> wrote:
> How old are the provincial boundaries in NL/Be?
>
> It seems strange that the lines between Noord-Brabant and Antwerpen
were
> not `rationalised' during the 15 years in which they were parts of
the
> same kingdom.
>
> --
> Anton Sherwood