
Since atleast the 15th century an image of a lady with a crown has been the emblem of the of the number one Livery company in the City of London, The Worshipful company of the Mercers. It can be seen all around London adorning the many properties owned by the Mercers. The strange thing is that no one can say how this image came to be adopted by the Mercers, formerly a Guild trading in luxury cloth.
The word "mercer" derives from the Latin merx, mercis, "merchandise" from which root the word "merchant" is also derived.
The origin of the “Mercers’ Maiden”, the heraldic emblem of the company, is not known. Unlike most of the City livery companies, the Mercers had no early grant of arms but the 1425 charter granted a common seal.

The Mercers website states this about its emblem: “The origin of the Mercers’ Maiden is not known and no one today knows what it meant or represented to the early Mercers. There are many theories, some more far-fetched than others. “
The Mercers company was only officially granted their coat of arms in 1911. The College of arms with the text accompanying the image have stated that the lady is the Virgin – this had been one of the persisting theories over the years. Over time this assertion recorded by the College of arms may become the accepted truth and so one day we may forget that it’s origin was once a mystery.
So since no knows for sure who the lady is, I’d like to put my own theory forward: The Saxon kingdom of Mercia was saved by her Queen, Daughter of Alfred the Great. The Danes, whose Kingdom was in the North of England, Danelaw would have almost certainly taken over the remaining English Kingdoms if it had not been for Aethelflaed who had become Queen of Mercia after marrying into the Kingdom of Mercia.
After Alfred the Great re-took London back from the Danes, he married his daughter to the Æthelred of Mercia and gifted London to Mercia. After Æthelred’s death, she ruled the Mercia between 911 and 918 AD. Aethelflaed not only showed genius in military defence but she also took the offensive and drove back the the Danes! She became known as the Lady of the Mercians.
Sadly her story was not very well documented and was rediscovered more recently, for her to finally receive her dues in the founding of England as we today know it; However, in her time, and many years thereafter she was well known in England, and even revered.
So perhap the Mercers honored the Lady of the Mercians and chose to have her image as their Emblem: because had it not been for Aethelflaed , City of London would not have been granted to the Mercia and England itself may have fallen to the Danes!
References:
- https://www.britannica.com/biography/Aethelflaed
- https://thehistorypress.co.uk/article/aethelflaed-lady-of-the-mercians-timeline/
- https://www.twinkl.co.uk/teaching-wiki/aethelflaed
- https://www.law.ua.edu/specialcollections/2016/07/18/aethelflaed-lady-of-the-mercians/
- https://www.heraldry-wiki.com/heraldrywiki/index.php?title=Worshipful_Company_of_Mercers