in the evening of may 21, orders arrived from the german supreme command to advance north and to take the channel ports. guderian at that point intended to take 10th panzer division via hesdin and saint-omer towards dunkirk, whereas 2nd panzer division was to attack boulogne-sur-mer and 1st panzer division calais, but this operation would be cut short by intervention from panzer group kleist, which determined at 06:00 on the morning of 22 may to hold back 10th panzer division as part of the army's reserves. before then, the corps leadership had given out the "vorläufiger korpsbefehl nr. 12" ('preliminary corps directive no. 12'), only to then, from the panzer group kleist, receive "gruppenbefehl nr. 12" ('group directive no. 12') (21:00 and 22:30 respectively). both of these orders elaborated on the allied forces trapped in the north (estimated at 30 to 40 in "gruppenbefehl nr. 12") and their attempts to escape over the english channel. although the removal of 10th panzer division by the army leadership in panzer group kleist weakened guderian's plan, in which the 10th panzer was to guard the right flank of the advancing corps, the general direction of movement stayed the same for the two remaining panzer divisions.""