CHEVAUX-DE-FRISE, a military obstacle, originating apparently in the Dutch War of Independence, and used to close the breach of a fortress, streets (French for "Friesland horses"; the Dutch Vriesse ruyters, "Frisian horsemen," and German Spanisclie Reiter, "Spanish horsemen"), etc. It was formerly of ten used in field operations as a defence against cavalry; hence the name, as the Dutch were weak in the mounted arm and had therefore to check the enemy's cavalry by an artificial obstacle. Chevaux-de-frise form an obstacle about 4 feet high, made of beams in which are fixed a number of spears, sword-blades, etc., with the points projecting outwards on all sides.