[1][page needed] When the 1st Cavalry Division was mobilized in late 1939, most of its regiments were at full strength.

The K-W line was fully breached and the 1st Cavalry Division retreated west.

The situation got worse when the Allied armies including the Belgians were encircled near Northern France and Flanders.

By May 25-26, the remainder of the division not yet killed or captured was again reorganized so they could be deployed in the Sluis Middelburg line.

But the line was breached yet again, as 1st Cavalry Division was withdrawn and had to defend the quickly built defense of Strobugge-Maldegem-Oostwinkel axis.