The sector between Thorn and Ell (in the west), bordering on the Wessem-Nederweert Canal was liberated in September/mid November by Belgian (and Luxembourg) troops, the Brigade Piron, which was part of the British Eighth Army Corps. It was an independent brigade named after its first commander, Colonel Jean-Baptiste Piron and consisted of soldiers who had escaped the German siege of the British Expeditionary Force in 1940. In the middle of Limburg, the only 1,400-strong Belgian-Luxembourg Brigade Piron had to defend a front roughly twenty kilometres wide between Ell and Heppeneert, a front line where normally an entire division of 13,000 troops would be deployed. The 7th Fallschirmjägerdivisie under General Erdmann was active in this area. The undermanned Brigade Piron was barely able to cope. The Germans built defensive reinforcements along the Wessem-Nederweert Canal and used Limburg forced labours to dig trenches and foxholes.

Before its liberation by the Allies, Thorn was occupied by a Fallschirmjäger battalion, backed by a company of the Waffen SS Landsturm Nederland. They carried out raids in the White Town, as Thorn was known. Thorn was liberated on the 25th of September, thereby placing it in the frontline. At that time, the situation was so dangerous the civilian population had, after all, to be evacuated; on the 6th of November, 1,500 of the 1,850 residents left the village. The British eventually succeeded in relieving the Brigade Piron on the 16th of November and permanently take out the German forces.