On 10 May 1940, Germany invaded Luxembourg, the Netherlands, and Belgium. The 4e DI was ordered to hold the line of the Sambre river. Hauteclocque was placed in charge of three infantry battalions. To his dismay, orders came to pull back to the Canal de l'Escaut. From there the 4e DI retreated northward, becoming encircled in the Lille pocket on 28 May. Hauteclocque received permission to escape through German lines. He attempted to make his way back to the French lines by pretending to be a civilian refugee, but was apprehended by a German patrol and taken prisoner when they discovered an old military pay receipt. He was taken back to a German command post, where he secretly destroyed the receipt. He convinced a German colonel that he had been wounded in Morocco, suffered from malaria, and had six children, all of which was true, and he was thus exempted from military service, which was false. The Germans let him go. He then made his way to the Crozat Canal, swam across, and encountered a French patrol.