Upvote:4
It depends...
While on TV it is dramatic for a commander to order a retreat, the proper command in the British Army is to "retire" (opposite to advance).
This would require a well ordered march away from the enemy.
Even a retreat would be reasonably ordered - although, not necessarily following a specific command. Retreats are generally a unit deciding for itself to pull back.
Retreats, however, quickly become routs - which are the more familiar "every man for himself" and "run fast" disorderly retreat.
Upvote:6
Armies would "march in formation while retreating" if not routed.
Maintaining formation was all important in a retreat. Most casualties were caused by armies falling apart and individual men being "picked off" by the enemy, usually cavalry, not in the battle itself. Hence, the sacrifice of a "few" men marching in order was considered necessary for the army to remain coherent and not be routed.
Retreating armies marched at "double time" (speed), that is 6 mph instead of 3 mph. Pursuing armies (other than cavalry) could not advance at such speeds without risking falling into disorder. Which is one reason why most orderly retreats were successful.