- 1a : an official at a tournament of arms with duties including the making of announcements and the marshaling of combatants
- b : an officer with the status of ambassador acting as official messenger between leaders especially in war
- c (1) : officer of arms (2) : an officer of arms ranking above a pursuivant and below a king of arms
- b : one that conveys news or proclaims : announcer
- c : one who actively promotes or advocates : exponent
Heralds were originally messengers sent by monarchs or noblemen to convey messages or proclamations—in this sense being the predecessors of the modern diplomats. In the Hundred Years' War, French heralds challenged King Henry V to fight. During the Battle of Agincourt, the English and the French herald, Montjoie, watched the battle together from a nearby hill; both agreed that the English were the victors, and Montjoie provided King Henry V, who thus earned the right to name the battle, with the name of the nearby castle.
Like other officers of arms, a herald would often wear a surcoat, called a tabard, decorated with the coat of arms of his master. It was possibly due to their role in managing the tournaments of the Late Middle Ages that heralds came to be associated with the regulation of the knights' coats of arms. This science of heraldry became increasingly important and further regulated over the years, and in several countries around the world it is still overseen by heralds. Thus the primary job of a herald today is to be an expert in coats of arms. In the United Kingdom heralds are still called upon at times to read proclamations publicly; for which they still wear tabards emblazoned with the royal coat of arms.