Roman Catholicism is, by far, the most popular religion in the country, with four in five Spaniards (80%) self-identifying as Catholics. The next group (one in eight, or 12%) is represented by atheists or agnostics. Minority religions account for one in seventy (1.4%) of all Spaniards.
The Romans arrived in the Iberian peninsula during the Second Punic war in the 2nd century B.C., and annexed it under Augustus after two centuries of war with the Celtic and Iberian tribes and the Phoenician, Greek and Carthaginian colonies becoming the province of Hispania. Some of Spain's present languages, religion, and laws originate from this Roman period.
In 1898 Spain lost the Spanish-American War. Cuba gained its independence, and Spain lost its remaining New World colonies—Guam, the Philippines, and Puerto Rico—to the United States. Spain's colonial possessions were reduced to Spanish Morocco, Western Sahara and Equatorial Guinea.
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.
According to the latest official poll, 80% of Spaniards self-identify as Catholic, 12% as non-believer, and 1% as other (the remaining 7% declined to state). Of the 1.4% identifying as other, 29% identified as Evangelical Christian, 26% as Jehovah's Witnesses and 3% as Muslim (the rest either mentioned smaller religions or declined to state). According to the same poll, 73% believe in God, 14% don't and 12% are unsure (1% declined to state). Additionally, according to this poll, only 41% believe in Heaven. 24% of the Spaniards think that the Bible is just a fable. Only 25% of Catholics go to church at least once a week.
As the Roman empire declined, the Suebi, Vandals and Alans each took control of part of Hispania. In the 5th century AD the Visigoths, a romanized germanic tribe, conquered all of Hispania and established a relatively stable kingdom lasting until 711, when it fell to an invasion by Islamic North African Moors and became part of the expanding Umayyad empire, under the name of Al-Andalus. When the Umayyad empire gave way to the Abbaside empire, an Umayyad exile established the Caliphate of Cordoba, effectively making Al-Andalus independent from the empire.
The first governments of the Republic, were center-left, headed by Niceto Alcalá-Zamora, and Manuel Azaña. In 1933, the right-wing CEDA won power; an armed rising of workers of October 1934, which reached its greatest intensity in Asturias and Catalonia, was forcefully put down by the CEDA government.
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.
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.
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.
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.
The expulsion of the Muslims was reputedly started by the first King of Asturias, named Pelayo (718-737), who started his fight against the Moors in the mountains of Covadonga (722). Later, his sons and descendants continued with his work until all of the Muslims were expelled. Meanwhile, in the east of the peninsula the Frankish emperors established the Marca Hispanica across the Pyrenees in part of what today is Catalonia, reconquering Girona in 785 and Barcelona in 801. It was a buffer zone against Islam.
In 1499, about 50,000 Moors in Granada were coerced by Cardinal Cisneros into mass baptisms and conversion. During the uprising that followed (known as the First Rebellion of the Alpujarras), people who refused the choices of baptism or deportation to Africa, were systematically eliminated. What followed was a mass flee of Moors, Jews and Gitanos from Granada city and the villages to the mountain regions (and their hills) and the rural country, however by 1500 Cisneros reported that "There is now no one in the city who is not a Christian, and all the mosques are churches".
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.