Whereas most clubs are scruffy hamlets hoping the world hasn't forgotten them completely, Real Madrid and Barcelona are empires. They are masters of self-aggrandisement, all royal flash and ermine undergarments. When two great pomposities meet, the results are spectacular and inevitable, in the same way the dying sun swallowing the Earth will be spectacular and inevitable, except that we get to witness this particular supernova via television and web streams of dubious legality.