Aragon is the heart of what was in the Middle Ages the Crown of Aragon, which also included regions like Valencia, Murcia, Catalonia, the Balearic Islands, Venice, the South of Italy, Sicily and some Greek colonies. In the Fifteenth century its King Ferdinand married Isabel of Castile and formed the Kingdom of Spain.Although it used to have its own language, Aragonese, and laws, over the centuries most of them were lost and it became more like Castile.Nowadays, Aragon, despite its large size, has a population of only 1 million, making it largely uninhabited, with a capital, Zaragoza, that holds over half the population. http://wikitravel.org/en/Aragon