Complete the indicated task to unlock the achievement.

Achievement	How to unlock
A long march	Succesfully retreat all the knights.
Brothers in arms	Retreat with two knights at the same time.
Khan Krum's wisdom	Complete level 27.
Mass evacuation	Retreat more than one knight on the same stage.
Miracle worker of Dunkirk	Complete level 70.
The Grande Armée antagonist	Complete level 53.
They never learn, comrade	Complete level 56.
Withdrawal	Start the retreat.