The tricorne or tricorn is a style of hat in a triangular shape, which became popular in Europe during the 18th century, falling out of style by the early 1800s. The word "tricorne" was not widely use
Italian tricorne hat, mid-18th century
French Musketeers of the Guard wearing tricorne hats in 1688
Horse Guard of the Guardia Civil wearing a stylized tricorne during a ceremony in Madrid, Spain
Chelsea Pensioners wearing their tricorne hats
A cavalier hat is a variety of wide-brimmed hat that was popular in 17th-century Europe. These hats were often made from felt, and usually trimmed with an ostrich plume. They were frequently cocked up
Tricorne
…hat remains in use in several countries to the present day as an item of ceremonial dress. The tricorne appeared as a result of the evolution of the broad-brim round Cavalier hat used by Spanish soldiers in Flanders during the 17th century. By pledging (binding) the brims, a triangular shape was obtained. This shape was favored…
Detail of Banquet of the officers of the Calivermen Civic Guard, Haarlem, 1627, by Frans Hals showing Dutch schutterij officers wearing cavalier hats.