OK. Some googling explains. The US references to “lancer” images bring up armoured knights and roman cavalry. In British English it specifically means the flashy uniformed light cavalry of the horse and musket era. It is a light, fast and dashing image, not the heavy, armoured kind. Specifically see things like Polish Lancers and Bengal Lancers. Googling Napoleonic Lancers will give some idea though I could not see an awesome silhouette.