From the website of the beret museum, courtesy of babelfish translation:

"Create by l'entreprise Blancq Olibet (manufacturer of berets since several generations), this museum makes it possible to discover all l?histoire and the secrecies d?un principal symbols of the Western South. L?*©pop*©e of the beret seems to begin dice XV*®me century. This noble cover-chief was knitted with wood needles. Aujourd?hui technology is with the service of the manufacture of the beret, of which the sizes, the colors n?ont ceased d?*©voluer with the liking of the modes, the areas, the times. This accessory of mode crossed the centuries and was carried by characters such as Greta Garbo, the Montgomery General or l?Abb*© Pierre. The museum occupies the 2 stages d?un beautiful building " Directory " in edge of river, to 20 km in the south of Pau in the Pyrenees."

We lived in Naples during the 50's, and the beret was very common, though it was the narrow beret, and not the floppy Basque rendition. As far as I know, the Italians did not feel that what they were wearing was a French hat. My father wore one for years (though in recent years he has gravitated to a chauffeur's cap). I dug though a box of old hats and found that all of his old berets were made in Italy. The Italian word is berretto, which is generally translated as "cap", instead of hat, although "cap" is considered to be a truncation of "Capello" which is the Italian word for hat (which just shows how pointless is probably is to try and figure any of this out anyway). Of course, it is the same word as the French use.

I rarely see berets in France, and when I spot one, I generally point it out to my wife, who has learned to tolerate such things. I see more of them in the winter, usually on old men who have not shaved in several days and are reading rumpled newspapers. I actually tried to buy a beret once, to take it back to give to my father for Christmas, but it turns out that it is much easier to find them in the States--

A couple of years ago, in the middle of a rain storm in San Francisco, I actually bought and immediately wore, a beret. I got it from an Italian gift shop and for the rest of the day, wherever I went, I got a special sort of respect.