The origin of this international geographical puzzle is in no way particular. In medieval Europe, feudalism as the predecessor of the nation-states, was an all-round system of land exchange and granting, in exchange for protection or lordship. However, land owners always kept those lands to themselves from which they could raise tax money or other earnings. Due to this feudal system, territories became split up in a patchwork of parcels that belonged to different owners (dukes, counts, landlords, …).

In Baarle at that time, things were not different: parts of the territory were owned by the Dukes (“Hertog”) of Brabant (Baarle-Hertog) and others by the Lords of Breda and later the House of Nassau (Baarle-Nassau). After the Middle Ages however, the distinction between these various parcels remained unchanged throughout history.

After the Napoleon wars and subsequently the return to the Ancien Regime (Congress of Vienna, 1815), the United Kingdom of the Netherlands was established, embracing the current Belgian and Dutch state. This would not last long, for fifteen years later, the independence of Belgium was declared in 1831. After the split between Belgium and the Netherlands, the border between the two new states had to be determined. Therefore three border commissions were needed.

The first border commission, instituted by the Treaty of Maastricht of 1843, led to the determination of the national border between Belgium and the Netherlands, but could not sort out the Baarle issue. As to the enclave borders, a warrant indicating the nationality of each of the various parcels in Baarle, was included in the Treaty.

The state frontier between Belgium and the Netherlands remained unresolved as regards Baarle until 1974. A second border commission then was appointed to fix over a 36 km stretch the continuous border between the border marks 214 and 215 (Poppel and Meerle, neighbouring villages of Baarle-Hertog/Nassau).

By then, the enclave borders had not been officially determined. To do so, a third border commission was established to fix these as official state borders. The measuring as to sort this out, took more than 15 years (until 1995)! Before 1995, many problems arose due to the arbitrary status of the enclave borders, the location of which no one knew for sure.