The design of the Aymeric Memorial Medal and Medallion is based on the medieval seal of Aymeric de Saint Maur, the Master of the Knights Templar in Britain at the time of the sealing of Magna Carta at Runnymede in 1215.

Aymeric was one of the most powerful men in Britain.

Aymeric worked with Archbishop Stephen Langton to produce the original draft of Magna Carta.  He was named by King John in Magna Carta and was present as a witness to the events at Runnymede, together with many of his Templar knights.  He was subsequently appointed to be one of the 13 nobles, led by his friend, the Earl of Pembroke, Sir William Marshall, to be the Council of State for the young King Henry III who succeeded to the throne after the death of King John. 

During the 12th and 13th centuries the Great Seal of the Grand Masters of the Knights Templar showed on one side a representation of the Church of the Holy Sepulchre in Jerusalem to which pilgrims travelled and the Templars sought to protect.  On the other side was the Order's symbol of two knights on one horse, indicating their vow of poverty.  Many Provincial Masters also used this seal, according to a document issued by Pope Innocent IV in 1251.

However, the symbol of the two knights on one horse was not used in Britain.  Instead the seal of successive Masters of the Knights Templar in Britain - for example, Richard of Hastings (1160-85), Aymeric (1200 onwards), Robert of Sandford (1241) and William de la More (1304) - all showed Jesus Christ as the Agnus Dei (Latin for the Lamb of God).  This also echoed the belief that Jesus came to Britain as a young boy with his 'uncle', Joseph of Arimathea - as indicated much later (1804) in William Blake's well-known and well-loved hymn: "Jerusalem":

And did those feet in ancient time
Walk upon England's mountains green:
And was the holy Lamb of God,
On England's pleasant pastures seen!

In heraldry the Agnus Dei is usually blazoned: "a lamb passant proper, with a halo or charged with a cross gules the dexter forelimb reflexed over a cross staff from which a pennon argent a cross gules (Saint George) is flotant".

The seal depicted on the Aymeric Memorial Medal is derived from one of the Templar seals in the British Museum which displays the Agnus Dei on the front, and the Church of the Holy Sepulchre on the reverse:

The medal's ribbon is based on the international arms of the Order:

and superimposed are three red stripes to represent the Great Banner of the Order: