Mermaids feature in medieval church decoration, often on capitals and misericords. Sometimes they have one tail but often they are depicted with two . They always seem to be wild haired despite the fact they are often depicted with comb and mirror which, if you were a medieval cleric, represented pride and luxury. I particularly like this misericord depicting a mermaid in Cartmel Priory Church. Her carver has left her with her hair half done. If you look to the right of the carving, you can see that one side is carefully plaited.
As for the mermaid herself she represented one of the seven deadly sins – lust. The mermaid and the siren (and perhaps its no surprise that the french for mermaid is sirene) both tempt men to risk not only their lives but also their souls.
Mermaids even made their way into the royal family during the reign of King Edward IV when he married Elizabeth Woodville. Her family claimed descent from Melusine, a two-tailed mermaid, who married Raymond of Poitou. Consequently, and somewhat bizarrely given a northern european tradition of mermaids being representative of sinful women, the french heraldic tradition includes double tailed mermaids and mermen being used on the field of the shield to symbolise eloquence.
As the centuries progressed the image of the mermaid continued to be used as an insult and euphemism for a prostitute. The people of Edinburgh depicted Mary Queen of Scots as a mermaid when she married Bothwell in May 1567, a few short weeks after Lord Darnley was murdered.
Gary Varner’s book entitled Strangely Wrought Creatures of Life and Death explores the folklore and traditions of mermaid. He speculates on their origins in prehistory as well as some of the symbolism attached to them.