How was a guidon shaped and used in battle?

In the context of heraldry, the guidon—a term derived from the French guyd-homme—was a flag similar in design to the standard but distinct in its shape. It was characterized by being either rounded at the fly or featuring two rounded swallow tails.1

Regarding its use in battle, the guidon served as a marker for military leaders who held a rank no higher than that of a knight. Because these leaders were not entitled to display a banner, the guidon functioned as their specific emblem on the field. While larger standards were intended to remain stationary to mark the position of high-ranking nobles or monarchs, guidons were carried by leaders directly in action.1