Historically, Flanders has been increasingly important. It's a fertile area and with its central location, forms an ideal spot for trade. This has been used to its advantage over the ages, to increase the wealth of Flanders and its people almost exponentially. There is, however, a backside to this. Spending so much time trading and generally getting rich, both financially, culturally and intellectually, puts less resources into an effective army. Over the ages, this has lead to Flanders being controlled by numerous people. Pre-Celts, Celts, Germanic tribes, Belgae, Romans, Franks, Burgundians, Spain, Austria, the Netherlands, Germany and now the buffer-state Belgium. Despite it having fallen to many foreign dictatorships over its history, the Flemish people are proud and when pushed too much, they do rise and can even defeat the mightiest of armies.
At the moment, the official language in Flandres is Dutch, with the native language being Flemish, which is a collection of many dialects. It's traditionally a Roman Catholic country, although thanks to the Enlightenment and proper education, religion is slowly being removed from society.