The layout of Spain's provinces closely follows the pattern of the
territorial division of the country carried out in 1833. The only major change of provincial borders since that time has been the division of the
Province of Canary Islands into the provinces of
Las Palmas and
Santa Cruz de Tenerife. Historically, the provinces served mainly as transmission belts for policies enacted in Madrid, as Spain was a highly centralised state for most of its modern history. The provinces were the "building-blocks" from which the autonomous communities were created following processes defined in the 1978
Constitution. Consequently, no province is divided between these communities. The importance of the provinces has declined since the adoption of the system of autonomous communities in the period of the
Spanish transition to democracy. They nevertheless remain
electoral districts for national elections. Provinces are also used as geographical references: for instance in
postal addresses and telephone codes. National media will also frequently use the province to disambiguate small towns or communities whose names occur frequently throughout Spain. A small town would normally be identified as being in, say,
Valladolid province rather than the
autonomous community of
Castile and León. In addition, organisations outside Spain use provinces for statistical analysis and policy making and in comparison with other countries including
NUTS,
OECD,
FIPS,
CIA World Factbook,
ISO 3166-2 and the UN's Second Administrative Level Boundaries data set project (SALB). Most of the provinces are named after their capital town, with the exceptions of
Asturias,
Cantabria, the
Balearic Islands,
La Rioja, and
Navarre — which are autonomous communities consisting of a single province — as well as the historically autonomous
Álava,
Biscay and
Gipuzkoa. The names of the provinces of
Las Palmas and
Castellón are taken from their respective capital cities, but shortened. In almost all cases, the capital of the province is also its biggest settlement, with the exception of the provinces of
Pontevedra (
Vigo),
Cádiz (
Jerez), and
Asturias (capital is
Oviedo, but largest city is
Gijón). Only two capitals of autonomous communities —
Mérida in
Extremadura and
Santiago de Compostela in
Galicia — are not also the capitals of provinces. Seven of the autonomous communities comprise no more than one province each: Asturias, the Balearic Islands, Cantabria, La Rioja,
Madrid,
Murcia, and Navarre. These are sometimes referred to as "uniprovincial" communities.
Ceuta,
Melilla, and the
plazas de soberanía are not part of any province. == List of provinces ==