The dictatorship of Miguel Primo de Rivera collapsed in 1930. Disgusted with the king's involvement in it, urban population voted for republican parties in the municipal elections of April 1931. The king was forced to resign and a republic was established.
The original peoples of the Iberian peninsula (in the sense that they are not known to have come from elsewhere), consisting of a number of separate tribes, are given the generic name of Iberians. This may have included the Basques, the only pre-Celtic people in Iberia surviving to the present day as a separate ethnic group. The most important culture of this period is that of the city of Tartessos. Beginning in the 9th century BC, Celtic tribes entered the Iberian peninsula through the Pyrenees and settled throughout the peninsula, becoming the Celt-Iberians.
With the approval of the Spanish Constitution of 1978 and the arrival of democracy, the old historic nationalities — Basque Country, Catalonia, Galicia and Andalusia— were given far-reaching autonomy, which was then soon extended to all Spanish regions, resulting in one of the most decentralized territorial organizations in Western Europe.
Spain was part of the Roman Empire and many areas of Spain retain significant Roman architectural remnants. The Roman aqueduct at Segovia is still in use as of 2004; Mérida, now the Extermaduran capital but once the capital of the Roman province of Lusitania, retains over 5 miles of its Roman aqueduct, Roman bridge over the River Guadiana, an arch of Trajan, and significant remnants of a Roman forum, amphitheatre, and a temple popularly accounted to have been dedicated to Diana (goddess). Another Roman bridge crosses the Tagus River at Alcántara. Lesser Roman ruins can be found in the heart of Barcelona.
On February 20th 2005, Spain became the first country to allow its people to vote on the European Union constitution that was signed in October 2004. The rules states that if any country rejects the constitution then the constitution will be declared void. The final result was very strongly in affirmation of the constitution, making Spain the first and so far only country to approve the constitution via referendum.
A revived movement for the Christian unification of Spain was capitalized on by the "Catholic monarchs" (Reyes Católicos in Spanish) Isabel I of Castilla and Fernando II of Aragón in order to justify their invasion of Granada, the expulsion of the Jews and the forceful conversion of the Moors. In the 15th century, the Kingdoms of Castile and Aragon were united under Isabel and Fernando. These two able rulers ruled jointly and worked to consolidate the power of the monarchy at the expense of the nobility. During their reign, the castles of many nobles (symbols of aristocratic independence from the monarchy) were demolished, and a system of regular taxation was established. Fernando and Isabel established the basis for the unification of Spain religiously as well as politically and economically.
Modern Spain began to take form during the Reconquista, the struggle between the Christian kingdoms arising in the northern regions left unconquered by the Moors and the Muslim kingdoms into which Al-Andalus eventually split.
Mainland Spain is dominated by high plateaus and mountain ranges such as the Pyrenees or the Sierra Nevada. Running from these heights are several major rivers such as the Tajo, the Ebro, the Duero, the Guadiana and the Guadalquivir. Alluvial plains are found along the coast, the largest of which is that of the Guadalquivir in Andalusia, in the east there are alluvial plains with medium rivers like Segura, Júcar and Turia. Spain is bound to the east by Mediterranean Sea (containing the Balearic Islands), to the north by the Bay of Biscay and to its west by the Atlantic Ocean, where the Canary Islands off the African coast are found.
Historically, various regions of Spain had quite distinct regional dress. Today, most people in Spain dress in a manner comparable to most other contemporary Europeans, although some regional variations persist. Dress in Extremadura and in the smaller cities of Castile remains relatively austere, even on festive occasions, while Andaluz dress on festive occasions is elaborate and ostentatious. Barcelona is one of the most stylish cities in Europe, though more restrained and with a more determinedly timeless style than Paris or Milan.
Spanish rule in Morocco ended in 1956. Though militarily victorious in the 1957-1958 Moroccan invasion of Spanish West Africa, Spain gradually relinquished its remaining African colonies. Spanish Guinea was granted independence as Equatorial Guinea in 1968, while the Moroccan enclave of Ifni had been ceded to Morocco in 1969.