Frequent mentions and appearances of beautiful women here lead me to attempt to redress the balance.
History gives as the ugliest woman ever Margarete von Görz, countess of Tyrol. She is maybe better known as Margarete Maultasch, which means Pocket-mouth, Bag-mouth. A strong character, she had many troubles, chiefly to do with producing an heir. She was married at twelve to a boy of eight. Dynastic needs eclipsed the lad's capabilities, so without bothering with divorce she married someone else, thereby alienating the lad's family. She defended herself against the charge of bigamy by claiming her first marriage was unconsummated. She was thereupon excommunicated, and it was perhaps at this time, telling everyone what she thought of them, that she earned her nickname.
Somehow the portrait up there at the top, the Ugly Duchess, by the Flemish artist Quentin Matsys, has been accepted as her likeness. This portrait appears to have been the model for Sir John Tenniel's Ugly Duchess (above) in Lewis Carroll's Alice's Adventures in Wonderland. While Tenniel's gives his Duchess a big mouth, Matsys' version tends towards the rosebud.
But there's something not quite right here. Margarete von Görz died in 1363, aged 51. Matsys painted his portrait in 1513, 150 years after her death. I don't know if Matsys ever claimed it represented Margarete von Görz. (It seems to me to have faint pre-echos of Tony Blair, as caricatured by certain cartoonists.) On the other hand much medical ink has been spilt claiming that what Matsys was illustrating, for reasons that are obscure, was a woman of some distinction, judging by her dress, in the toils of Paget's disease. This is a bone disease causing horrible deformities. Matsys' Duchess has all the symptoms. But why did he paint her?