The French chasseurs have charged the British hussars covering the approach of 1st corps. The hussars failed their morale, and met the charge at the halt. They immediately broke and routed through the infantry behind them. The chasseurs failed their morale, and pursued the hussars. The infantry brigade which the hussars had ridden through made their morale, and managed to form square, which caused the chasseurs
Both the French chasseurs and the British infantry in square are disorganized. The remainder of 1st British corps are still in column of march, and will be exposed to an opportunity charge by the chasseurs next turn.
A brigade which is charged by the enemy must make morale to counter charge. The British hussars rolled a 1, and failed their morale. They have to remain stationary, which is minus 2 in the subsequent cavalry melee. The French chasseurs rolled 10 on 2D6, and the hussars broke without fighting. Two casualties on the hussars, none on the chasseurs.
A cavalry brigade which routs the enemy must test their morale to see if they pursue. If they do so, as in this case, they roll another dice to see whether they pursue the brigade which they routed, or the nearest enemy.