A gang of Norman dandies. 

Even though in reality the Normans, or in other name Vikings, may not had been the first mass'ed group of dandies known to this world, this union definitely was one of the most influential across Europe in the 8-11th centuries. The Normans are known to be offsprings of Scandinavia, namely Denmark, Iceland and Norway, who used to undertake sea raids in order to empty and/or invade a certain country. This group of warriors-barbarians is also known for occupying the northern region of France which is now called Normandy, as well as southern Italy and eastern England. For a historical note, later on the Normans settled down in those regions by mingling with locals.
What's so important about the Normans and why could they be called one of those first original dandies in history? Well, apart from their passion towards conquering, intrigues and all the fanciest stuff Europe, especially France, Italy and England, possessed, these dandies seemed to kind of shock King Charles' spies with shaved and shorn hairstyles as if they all were priests. But the most interesting feature of the Normans is their adaptability, as with time shaved heads were abandoned in favor of long flowing locks inherent to yellow-haired English people. Plus they have adopted the French language and manners. Thus, Scandinavian dandies turned into European ones.

Image Courtesy: Palermo.com, BritishBattles.com