Belgium as successor of the kingdom of Holland. The northeasterly angle of the Department of the Ourthe, which the Neutral Territory occupied, was at the point of junction of that department with the French departments of the Meuse on the north, and of the Roeure on the east.
When it became a question of dividing this corner of the French Empire, the final act of the Congress of Vienna prescribed in Article 25 that in the "former Department of the Ourthe the five cantons of St. Vith, Malmédy, Cronenberg, Schleiden, and Eupen, and the extreme point of the canton of Aubel to the south of Aix-la-Chapelle, shall belong to Prussia; and the frontier shall follow the boundaries of those cantons in such a manner that a line drawn from the south to the north shall strike the said point of the canton of Aubel, and be continued to the point of contact of the three ancient departments of the Ourthe, the Roeure, and the Meuse."
In accordance with these provisions, which were accepted by Holland, the cantons of St. Vith, Malmédy, etc., as well as the eastern point of the canton of Aubel, cut by a line running direct from north to south from the point of junction of the three former French departments of the Ourthe, the Meuse, and the Roeure, were definitely assigned to Prussia.
It was now a question to determine the southerly point of this line, which, in following the above-named boundaries, did not coincide with the stipulations in Article 66 of the same act of the Congress of Vienna, which were intended to define the future frontier of Holland, now Belgium. It was therein provided that "the frontier shall run along these limits to their point of contact with those of the aforesaid canton of Eupen, and following in a northerly direction the westerly boundary of this canton, leaving at the right a small portion of the above French canton of Aubel, shall meet at the point of junction of the three former departments of the Ourthe, the lower Meuse, and the Roeure."
