The plate armour of European soldiers did not stop soldiers from moving around or necessitate a crane to get them into a saddle. They would as a matter of course fight on foot and could mount and dismount without help. In fact soldiers equipped with plate armour were more mobile than those with mail armour (chain armour), as mail was heavier and required stiff padding beneath due to its pliable nature. It is true that armour used in tournaments in the late Middle Ages was significantly heavier than that used in warfare, which may well have contributed to this misconception.

Plate armour is a historical type of personal armour made from iron or steel plates, culminating in the iconic suit of armour entirely encasing the wearer.

While there are early predecessors such as the Roman-era lorica segmentata, full plate armour developed in Europe during the Late Middle Ages, especially in the context of the Hundred Years' War, from the coat of plates worn over mail suits during the 13th century. In Europe plate armour reached its peak in the late 15th and 16th centuries, and the full suit of armour, commonly perceived as "medieval", was actually only a feature of the very end of the Middle Ages and of the Renaissance period. Full suits of Gothic plate armour were worn on the battlefields of the Burgundian and Italian Wars.

The use of plate armour declined in the 17th century, but remained common both among the nobility and for the cuirassiers throughout the European wars of religion. After 1650, plate armour was mostly reduced to the simple breastplate (cuirass) worn by cuirassiers. This was due to the development of the flintlock musket which could penetrate armour at a considerable distance, severely reducing the payoff from the investment in full plate armour. For infantry, the breastplate gained renewed importance with the development of shrapnel in the late 18th century.