Religious tensions were increasing in Spain. Conversos were not fully trusted; there was an increasing fear that many were secretly practising Judaism. Isabella was concerned that it would be easier for conversos to maintain their faith if the temptation of Judaism was removed. Popular anti-Semitism was growing. Convivencia was beginning to break down. Clashes between Old Christians and conversos took place in Toledo in 1467 and in Cordoba in 1473, largely because conversos held important roles in government and commerce. Ferdinand and Isabella responded by instigating the inquisition in 1478 – part of a deliberate policy to strengthen the church, which would in turn support the crown. The prime target of the inquisition in its early years were the conversos; in Barcelona from 1488-1505, 1200 people were tried by the inquisition, of whom only 8 were not conversos. The inquisition culminated in a decree issued on the 31st March 1492 – requiring all Jews to become Christians within four months or leave the kingdom. There are understandable criticisms of the inquisition. It spread fear and stifled religious debate. Inquisitors were sometimes unregulated – such as Diego Rodriguez Lucero, Inquisitor of Cordoba from 1499, who arrested and executed many on false charges. Besides this, the loss of many Jews to North Africa had a detrimental economic impact – many had occupied important posts. Of those that stayed, many of the Jews who ‘converted’ in 1492 continued to practise Judaism secretly. Although the new policy of limpieza de sangre created a less tolerant Spain than had existed under the idea of convivencia, it did increase the Catholic Church’s support for the crown, strengthening Ferdinand and Isabella’s position. The inquisition at least spared Spain the religious conflict rife in many parts of Europe in the sixteenth century; it succeeded in enforcing religious uniformity. France, Germany and England were all divided by religious wars – the inquisition ensured that this did not happen in Spain.
The military orders of Santiago, Alcantara and Calatrava in Castile, and of Montesa and St. John in Aragon had become very powerful military organisations, which might not support the crown in a crisis. They were dominated and exploited by the nobility, were wealthy in land and treasure and did not observe their religious duties – in 1540 the members of two orders were allowed to marry. However, Ferdinand and Isabella dealt successfully with the problem posed by the military orders. Isabella had been keenly involved in gaining control of them; when the Master of Santiago died in 1476 she visited the electors to suggest they choose Ferdinand. Although not officially confirmed by the Papacy until 1523, by 1494 the military orders had effectively become a branch of government.
Ferdinand and Isabella wished to end the long-running reconquista by taking control of the last Moorish stronghold in Spain - Granada. Throughout the fifteenth century the Castile-Granada border had been the site of Christian-Muslim skirmishes. In April 1478 the Moors attacked the Christian town of Cieza, killing 80 of its inhabitants and capturing the rest. After a ten-year long war, in 1492 Granada was under the control of Ferdinand and Isabella. Initial treatment of the Mudejars was lenient; however in 1499 a policy of forced conversion was adopted. Similarly to the Jews’ expulsion in 1492, this caused many economically useful citizens to flee to North Africa. However, the policy was effective in enforcing religious uniformity. In 1494 Pope Alexander VI described Ferdinand and Isabella as ‘athletes of Christ.’ The campaign increased the Church’s favour towards the Catholic Kings as they were seen to be rooting out heresy. It also temporarily united their kingdom in a common cause.
The Church was in need of reform under Ferdinand and Isabella. The clergy were exempt from taxation and were outside the scope of the royal justice system. Leading churchmen were aristocrats with independent ideas – they were invariably wealthy; abuses were rife. Some bishops had enormous and potentially dangerous powers – for example, the Archbishop of Toledo had 20 fortified towns and a military force of 2000, which had sided with Joanna against Isabella in the war of succession. Parish clergy, meanwhile, were frequently poor and uneducated. With the support of Isabella’s confessor Cisneros, Ferdinand and Isabella pursued a policy of reforming religious education. Cisneros attempted to move the church away from spreading corruption – by appointing bishops of sound moral and intellectual standing. The University of Alcala opened to educate future bishops, and higher clergy were chosen who were pious, celibate, Spanish and University educated. This excluded the nobility from church offices, who had not generally been to university. Absenteeism and pluralism were reduced as the number of priests increased, and residency was enforced. Patronato was an integral part of Church reform. Initially, the appointment of bishops lay with the Papacy, which weakened royal control. The Catholic Kings were successful in gaining patronato over all church appointments in Granada and the Canaries in 1486. They assumed that it would also be granted for the establishment of new bishoprics in New Spain – however, the papal bull of 1504 refused to acknowledge royal authority. It was not until 1508 that the Pope relinquished control. In 1493 the Pope authorised the crown to investigate monastic houses. However, Ferdinand and Isabella did little more than establish the right to do so; visitations were often not as rigorous as intended. Monastic houses suffered from indiscipline, lax observance and a lack of external control. Ferdinand and Isabella left much reform still to take place by the time of their deaths; however, they had gone a significant distance towards their goals.
Ferdinand and Isabella were significantly successful in dealing with many of the religious problems encountered during their reign. Church reform seems to be an area where they achieved least; this is not particularly unexpected since the need for it did not pose an imminent threat to the security of Ferdinand and Isabella’s kingdom. Perhaps most important in measuring their success is the fact that Spain did not descend into widespread religious conflict in the sixteenth century, unlike many other states in Europe at the time.