guderian and the staff of xix army corps was called into position at their initial headquarters at bitburg on 9 may 1940 at 13:30. guderian reached the troops by the evening and had them assemble along the border to luxembourg, taking positions between vianden and echternach. the invasion was to start the next day. the first major operational target for xix army corps would be sedan, france. karl-heinz frieser identifies the sedan sector under x corps (pierre-paul-jacques grandsard) on the left flank of the french 2nd army as the weakest part of the defensive line. charles huntziger, commander-in-chief of the french 2nd army, said as late as 7 may 1940 that he did not believe "that the germans will ever consider attacking in the region of sedan".