Medieval Coat of Arms History
The Hereditary Coat of arms belonging to families were first introduced at the commencement of the 12th century, the time of the Crusades. Numerous armies were engaged in the expeditions to the Holy Land, consisting of the troops of twenty different nations, they were obliged to adopt some ensign or mark in order to marshal the vassals under the banners of the various leaders. The regulation of the symbols by which the Sovereigns and Lords of Europe were distinguished was entrusted to the Heralds who invented signs of honour and made general regulations for their display on the banners and shields of the leaders of the different nations.

Early Medieval Coat of Arms
During the early Medieval period of the Middle Age when the Feudal System prevailed, not only in England, but other parts of Europe, none but military chieftains bore Coats of Arms.

Medieval Coat of Arms held by the Nobility
Few people held land under the Crown other than by military tenure, that is, under the obligation of attending in person with a certain number of vassals and retainers when their services were required by the king for the defence of the state. Heraldic honours were confined to the nobility, who were the great landholders of the kingdom.

Medieval Coat of Arms held by Knights
As time went by knights were allowed to bear a Coat of Arms. When lords and members of the nobility granted any portion of their territory to their knights and followers as rewards for deeds of prowess in the field or other services, the new possessors of the land retained the arms of their patrons with a slight difference to denote their subordinate degree.

Medieval Coat of Arms - Symbols used to distinguish the bearer
The ingenuity of the armorist was used to find a multitude of devices to distinguish every family. And when chivalry became the prevailing pursuit of all that sought honour and distinction by deeds of arms and gallant courtesy, the knights assumed the privilege that warriors in all ages have used - that of choosing any device they pleased to ornament the crests of their helmets in the field of battle, or in the mock combat of the tournament.

Medieval Coat of Arms - Jousting Tournaments
A knight was known and named from the device used as his crest. The heralds at jousting tournaments  introduced a knight to the judges of the field, or to the lady that bestowed the prizes, according to his Coat of Arms. A knight might therefore be referred to as the Knight of the Swan, the Knight of the Lion, without mentioning any other title. And knights whose fame for gallantry and prowess was firmly established, had their crests painted over their coats of arms.

Medieval Coat of Arms extended to the non-military
In the late Medieval period the kings of Europe decreased the power of the powerful nobles and lords. Lands and estates were bestowed together with titles not only for deeds of arms, but also for wisdom in council, superior learning, and other qualities which the original bearers of arms thought beneath them. The heralds were obliged to invent new symbols in emblazoning the arms of the modern nobility.  Coat of Arms were granted to civic and commercial corporations and to private individuals who had no claim to military honours. Eventually people were allowed to make an application for the right to bear a Coat of Arms see - Shakespeare Coat of Arms

Different symbols used on a Medieval Coat of Arms
The sun, moon, stars, comets, meteors were introduced on the coat of arms to denote glory, grandeur and power. Lions, leopards, tigers, serpents, stags were used to signify courage, strength, prudence and swiftness.
Trees, plants, fruits, and flowers were also used to denote the rarities, advantages, and singularities of different countries. Not only were natural and artificial figures used, but also fabulous animals from mythology such as dragons, griffins and harpies.

Medieval Coat of Arms that indicate a profession or surname
Some Coat of arms feature indications of the profession or the surname. Common shield designs included a pun on the family name. The name Chandler indicated that the family profession was as candle makers and the name Frobisher was given to those who polished armor and swords and suitable symbols on Medieval shield designs would reflect these names. Surnames also create opportunities for animals to be shown such as Swynford (swine or boar).