The Houx weir

North of Dinant, at Houx, the Meuse presents a peculiarity: an old weir-and-lock, extended by a dike, reaches an islet in the middle of the river, offering a passage on foot — narrow, slippery, but crossable without bridge or boat. During the night of 12–13 May, the German advance guard (motorcyclists and reconnaissance elements of Rommel's division) spotted this route.

The French defence of the sector, convinced that the Meuse was a secure obstacle, kept poor watch over this singular point, at the junction of two units. The German advance guard had to decide. It could attempt at once, by night and in silence, to send infantry across by the dike to establish a bridgehead on the west bank. It could wait for the regular crossing equipment (boats, bridges) and artillery support. Or it could simply report the passage without committing to it.

The stakes were considerable: a bridgehead, however tiny, established by surprise during the night would undermine the entire defence of the Meuse north of Dinant, at the poorly guarded hinge between two French armies.