Honi soit qui mal y pense.
uh-nee swah kee maa lee PAHSS. Click below to hear this.
Shame be brought on him who thinks evil of it.
This is not, as is sometimes supposed, the motto of the United Kingdom, though it appears on the Royal coat of arms. It is the motto of the Order of the Garter, an ancient and prestigious order of knighthood. The motto is also used on numerous military coats of arms.
There are various stories claiming to explain the origin of the phrase; you can believe all or none of them, if you like. (You can read all about those theories, and about the complex rules and history of the Order of the Garter, on Wikipedia at this link.)
Our interest here is the French, however. Why is the motto in French, anyway? Whatever its true origin, it dates to the 14th century, under the reign of Edward III, in an era when French was widely spoken in England.
You will find numerous spellings of Honi soit qui mal y pense. That’s because the French language was still evolving rapidly, and spelling was the least of anyone’s worries. There was no standardization. So you may see versions where the letter i always appears as y, or where the s becomes a c, or where qui becomes ki, ke, or que. About the only word that never seems to vary is mal.
The key concept here is honi (or honni). It means more than ashamed. The most commonly-told story about the motto’s origin (quite possibly apocryphal, and by no means the only tale) is that King Edward was dancing with his cousin Joan of Kent when she experienced a “wardrobe malfunction”: her garter slipped down to her ankle. The king gallantly picked it up and put it on his own leg, silencing the snickerers by saying Honi soit qui mal y pense! In other words, if you laugh at this lady’s misfortune, you are laughing at me, the king. And we all know that laughing at the king just isn’t done!
As for the grammar, qui mal y pense is very old usage. In modern French, y stands for almost any preposition except de + a noun. But penser à means to think about, to occupy one’s mind with, while penser de means to think of, to have an opinion about. That would call for en, in this sentence, not y. An y is just not done here.