France was perceived as the "home" of Western European fashion during the 18th and 19th centuries. (I'm not as familiar with the sources prior to the 18th century, so I can't say how far back this association goes, but we do know of English people importing luxurious French clothing in preceding centuries as far back as the 16th century, at least.) The French luxury industries were promoted domestically by Louis XIV during his reign, most notably in his requirements for the nobles at court - which led to these industries' growth and improvement. His finance minister, Colbert, ruled that new silks would be produced seasonally (spring and fall), creating a planned obsolescence. The first true fashion plates (as opposed to illustrations of the regional dress of different nations) were published in Le mercure galant, a publication begun in 1672, which described the new spring and fall fashions in Paris; the illustrations didn't stick although the descriptions did, but fashion plates began to be published in separate, unaffiliated folios and eventually came back to regular publication in magazines in the 1770s. The French fashion industry changed its products regularly, and change is the essence of fashion.

Unfortunately, I can't help with the question of outlandishness.