A cavalier is a fortification which is built within a larger fortification, and which is higher than the rest of the work. It usually consists of a raised platform within a fort or bastion, so as to be able to fire over the main parapet without interfering with the fire of the latter.[1] Through the use of cavaliers, a greater volume of fire can be obtained, but its greater height also makes it an easier target for a besieger's guns.[2]
There are two types of cavaliers:
Common cavalier – a raised gun platform without any additional defensive features
Defensible cavalier – a raised gun platform surrounded by a ditch. If the ditch cuts across the bastion's terreplein and is supported by cuts, the cavalier can also be considered as a retrenchment.[3]