It is usually recognized for its language, Catalan, spoken by more than 8 milion people around the world.
Catalonia is one of the first most important centers from the first Neolithic in the Occidental Mediterranean, so as from the second.
It sufered the invation of the Greeks in the fifth century (BC) and the romans in the 3d century (BC) which represented big social movements; the muslim invasion and so.
It was a well known independent kingdom till the XIV century, when it took part in the spanish empire. And finally in the XVII and XVIII century, La guerra de sucesión (the succession war) finished with the political independence of Catalonia.
Nowadays Catalonia still has its culture, language, monuments, humor and people...being so diferent from the spanish.
But yeah, I guess it doesn't deserve being recognized independent, after all, spaniards got here first, right?