Gules is a heraldic term that refers to the color red. In heraldry, colors are used to represent different qualities and characteristics, and gules symbolizes courage and valor. It is one of the most commonly used colors in coats of arms and flags. In heraldic designs, gules is often depicted as a solid red field. It can be combined with other colors and symbols to create unique emblems. The use of gules can be traced back to medieval times, where it played a significant role in identifying noble families and their lineage, such as the House of Lancaster.