马甲是一种用来保护战马的铠甲，早期为西亚游牧民族所使用，后来随着罗马帝国传入欧洲。二世纪时，帕提亚帝国、罗马帝国骑兵队会为战马披上锁子甲或小鳞甲，十五世纪左右欧洲骑士也会给座骑装备板甲。

Barding (also spelled bard or barb) is armour for horses. During the late Middle Ages as armour protection for knights became more effective, their mounts became targets. This tactic was effective for the Scots at the Battle of Bannockburn in the 14th century when horses were killed by the infantry, and for the English at the Battle of Crécy in the same century where archers shot horses and heavy infantry killed the French knights after they were dismounted. Barding developed as a response to such events.