The Spanish Administrative Division is claimed considered to be too complex. To understand it, we need to have keep in mind that there are two kinds of territorial demarcations in Spain; one superimposed over the other.
     On the one hand, we have the provinces. This subdivision was created in the 18th century, after the Succession War. The new Borbon King, Felipe the Fifth, needed to divide his kingdom in little, and homogeneous demarcations administered by royal representatives, in order to impose the absolutist and centralized model of France. The other purpose of the measure was to dissolve the sovereignty of the former kingdoms, like Aragón, Catalonia or Valencia.
     Provinces are claimed to be artificial districts, but many of them were based in on "little kingdoms" from the Medieval Age, and if you see study the boundaries, they do not seem to be traced with rulers. Nevertheless, after two centuries of history, a feeling of community based in the provinces has been developed; after all people from the villages usually traveled to the capital towns, because many public services were centralized there.
     On the other hand, there are the regions or “Autonomous Communities." They were ideated initiated during in the Second Republic (1931-1936), as an intermediate solution to for the issues between a centralized State and a Federal one, in order to satisfy the nationalist demands of some historical regions, like Catalonia or Basque Country. The solution was recovered after Franco’s death, but then it was seen as another kind of homogeneous territorial division, so many regions without the same historical connotations acceded to this status. Because of this, nationalist movements are arising again. nowadays Regions are self-governing in some subjects matters, and share other competencies with Madrid.

Very good, Shy Spaniard! Let me know if you have questions about the corrections. Muy bueno, Senorita Tímida! Déjeme saber si tienes preguntas acerca de las correcciones.