The Catholic Church in Spain is part of the Catholic Church under the spiritual leadership of the Pope in Rome, and the Spanish Episcopal Conference.
According to romans 15:28 in the Romans, Roman Catholicism and Christianity as whole began in Spain when St. Paul went to Hispania to teach the gospel there after visiting the Romans along the way. After 410 AD, Spain was taken over by the Visigoths who had been converted to Arian Christianity around 360. From the 5th to the 7th century, about thirty synods, were held at Toledo to regulate and standardize matters of discipline, decreed uniformity of liturgy throughout the kingdom. Medieval Spain was the scene of almost constant warfare between Muslim and Christian kingdoms. Muslim and Christian people lived in peaceful co-existence under Muslim rule such as in Al-Andalus with many instances of inter-religious marriage. However, there was tension frm the Pope and the Catholic Church to oppose Muslim rule in Spain and to "reclaim" Europe. This was the period of the so-called Golden age of Jewish culture in Spain. The Almohads, who had taken control of the Almoravids' Maghrebi and Andalusian territories by 1147, far surpassed the Almoravids in Islamic fundamentalism, and they treated the non-Muslim dhimmis harshly. Faced with the choice of death, conversion, or emigration, many Jews and Christians fled to North Africa and Egypt.
The Reconquista was the long process by which the Catholics reconquered Spain from Muslims by 1492. The Spanish Inquisition was established in 1478 to complete the religious purification of the Iberian Peninsula. In the centuries that followed, Spain saw itself as the bulwark of Catholicism and doctrinal purity.