On the so-called ‘Island of Osen’, German troops had established a small but strategic bridgehead. Thanks to its location near the lock canal, a short, manageable waterway, they could offer much more effective resistance than along the kilometers-long bend of the Meuse near Linne.

On December 6, 1944, the British attempted to capture the lock complex but this wasn't easy. The terrain around the lock was heavily defended and littered with mines and the attack took place under difficult conditions. Therefore they only partially succeeded in gaining ground and the island itself remained in German hands.

After this failed breakthrough, an exceptional situation arose: the Allies occupied the lock keeper's houses on one side while German troops held their ground on the island and on the opposite side. Both sides faced each other at a distance of only a canal width. This led to a prolonged stalemate from early December 1944 to late February 1945.

The Allied troops who held their ground here became known as the “Lock Force”, named after their position at the lock. Life at the front was harsh: cold, mud, mines, and constant threats defined the soldiers' daily existence for months.

It was not until late February 1945 that movement began on the front when American troops reached the area. On the night of February 25, they crossed the channel and one day later the island of Osen was finally captured.