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.
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.
The crown jewel of Spain's next decade of infrastructure construction is the Spanish high speed rail network, Alta Velocidad Española AVE. Currently, an ambitious plan includes the construction of a 7000 km network, centered naturally on Madrid. The overall goal is to have all important provincial cities be no more than 4 hours away from Madrid, and no more than 6 hours away from Barcelona. Currently, AVE high-speed trains link Atocha station to Seville in the south and Lleida in the east (to be extended to Barcelona).
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.
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.
Through a policy of alliances with other European nobility and the conquest of most of South America and the West Indies, Spain began to establish itself as an empire. The Treaty of Tordesillas, negotiated by Pope Alexander VI between Portugal and Spain, effectively divided up the non-European world between these two budding empires. Massive amounts of gold and silver were imported from the New World into Spain's coffers. However, in the long run this hurt the Spanish economy much more than it helped it. The bullion caused high inflation rates, which undermined the value of Spain's currency. Additionally, Spain became dependent on her colonies for income, and when Queen Elizabeth I of England began to capture Spanish vessels on the way to and from the New World, Spain suffered massive economic losses. These effects, combined with the expulsion of Spain's most economically vital classes in the late 15th century (the Jews and the Moors), caused Spain's economy to collapse several times in the 16th century, bringing the Golden Age of Spain to a close.
The dry weather of Spain resulted in the importance of water fountains in Spanish urban design. In addition, ceramics figure prominently in architecture throughout Spain, especially in the tile roofs and the use of decorative tiles known as azulejos.
Contemporary Madrid came into its own after the death of the Fascist dictator Franco. Years of the Franco regime left Madrid and much the country in economic shambles due to isolation. With his death, Madrid and Spain as a whole began to re-assert itself on the international stage. Within Spain, reaction against the dictatorial bureaucracy centered in Madrid and a history of centralism that pre-dated Franco by centuries has resulted in the successful modern movement towards increased autonomy for the regions of Spain, considered as European regions, under the umbrella of Spain.