Rome ruled Spain for nearly 600 years. Roman conquest of Spain began during the second Punic War (218-201B.C.). However, it took their army almost 200 years to conquer the entire region. Once having the entire Iberian Peninsula under their rule, they divided it into three provinces. Each province was governed separately. The province of Lusitania was in the west where modern Portugal is located. Baetica province was located in the south. In the center, north, northwest and eastern coast above Cartanega was the largest province, Hispania Tarroconensis. Civilization was unified under Roman rule. Governors were appointed from Rome to the provinces. The governors also gave positions of influence and power to indigenous leaders who were to help rule the peninsula. Common Laws, common language and communication were established unifying the provinces and strengthening the Roman's rule. Latin had become the official language.
Provinces within the region worked together to build roads to connect cities and aqua ducts for dry lands. The remains of the aqua ducts constructed are still standing today. Hispania became the wealthiest region in the Roman Empire. The large estates or villas they built controlled the large amount of peasant laborers and slaves. Small farms existed along the side of these large villas. They were often used as small holdings to be granted to the Roman army veterans in order to help colonize new lands, thereby, expanding their wealth. They traded minerals, oil, wine, wheat, and other products, which were produced in abundance.
The most significant contribution under Roman rule was the spread of Christianity. Today, Roman Catholicism, which became the official religion by 587A.D., is the religion of ninety-seven percent of the population. Christianity had first entered Spain in 300A.D.
The pagan religions made it difficult for conversion to Christianity. Christians were persecuted for wanting to practice their religion. During the Roman's conquest of Spain, many soldiers belonged to pagan cults. Iberians, Phoenicians, Greeks, Cartaginians, and other tribal settlers such as the Basques and Celtiberians, were known to have practice pantheistic religions. Each city had its special deity, usually known as Baal or lord. In all the cities the temple was the center of civil and social life, i.e., human sacrifice to the principal gods, by the Carthaginians. Many of the soldiers were not Romans but worked for the Romans as its empire expanded. This made it politically risky for Rome to push aggressively for Christian conversion. However, under Emperor Constantine the Great, Christianity was officially legalized. Christians were no longer persecuted with the freedom granted to practice Christianity. By 600 A.D. Christianity was well established throughout the entire provinces of Spain.
