The Crown of Aragon was a composite monarchy, also nowadays referred to as a confederation of individual polities or kingdoms ruled by one king, with a personal and dynastic union of the Kingdom of Aragon and the County of Barcelona. At the height of its power in the 14th and 15th centuries, the Crown of Aragon was a thalassocracy controlling a large portion of present-day eastern Spain, parts of what is now southern France, and a Mediterranean "empire" which included the Balearic Islands, Sicily, Corsica, Sardinia, Malta, Southern Italy and parts of Greece. The component realms of the Crown were not united politically except at the level of the king, who ruled over each autonomous polity according to its own laws, raising funds under each tax structure, dealing separately with each Corts or Cortes. Put in contemporary terms, it has sometimes been considered that the different lands of the Crown of Aragon functioned more as a confederation than as a single kingdom. In this sense, the larger Crown of Aragon must not be confused with one of its constituent parts, the Kingdom of Aragon, from which it takes its name.