The 1st Panzer Division continued to push forward, reaching the Channel coast near Calais on 23 May 1940, where they encountered heavy British resistance. The 10th Panzer Division was tasked with taking Calais, while Guderian ordered the 1st Panzer Division to head for Gravelines.&lt;/ref&gt; Elements of the 1st Panzer Brigade and the subordinated Infantry Regiment (motorized) Großdeutschland reached the Aa river south of Gravelines that night, southwest of Dunkirk. Strachwitz went on one of his "solo runs", penetrated the French and British lines and almost reached Dunkirk, where he observed the evacuation of British and allied forces by sea, which he reported to his commanding officer and the divisional staff.