There had been an Inquisition in Spain before in 13th Century Aragon, and was used for the detection, trial and punishment of heresy, but it had become redundant. So it wasn’t really founded during Isabella and Ferdinand’s reign, only reintroduced. However, this reintroduction was very important as it paved the way for a lot of changes within their Spain.The main reason for the reintroduction was because of the perceived growing threat of conversos. Because of some wealthy conversos, it meant they were in powerful positions. Pious Isabella also swore that there was a plot by them, and was convinced that they had no loyalty and were capable of treachery, and this led to a concern over the number of conversions that were taking place.It was introduced in Castile in 1478 and Aragon in 1484, and was under the monarchs’ control. It took a hard line and the Inquisition gained itself a reputation as something to be feared, and rightly so because between 1483 and 1495, burned around 2000 conversos as heretics.This happened at auto de fe’s whose purpose was to act as ‘burning festivals’, “ since the fire is lit it will burn until… not one of those who judaized is left”. The Inquisition used them as warnings to others.The Inquisition became a vital institution, and was extended because up to 1495, there were 15 regional tribunals set up throughout Spain. They had a general council, “Suprema” which was set up to coordinate and control operations in both Castile and Aragon. It united the crowns in “pursuit of common religious objectives”, which was probably the only thing in which the 2 kingdoms were ever joined. It was protected by the crown and papacy and had the support of the vast majority of the “Old Christian” community.The reintroduction of the Inquisition had a good outcome for Isabella and Ferdinand. For one it increased their control of the church in Spain. For example, in November 1478, the Pope gave authority to the monarchs to appoint bishops themselves (and other posts e.g. Inquisitors). This meant they could appoint their own people as it were, and gain a network of people on their side.Another outcome was it spread Isabella and Ferdinand’s spiritual control and influence over the people. This was because of success based on the fear the Inquisition generated. This fear stemmed from its methods of working in secret and the great power it held – “life and death”.However, the Spanish Inquisition wasn’t perfect and there were bad things about it. For example it was expensive to run, and even though it gained the property of the people it convicted this wasn’t enough to keep it going, so the suggestion that the introduction of the Inquisition was due to the desire for money is unlikely. Also it had a number of internal abuses with a potential for misuse.The Inquisition was also accused of harsh treatment, “many innocent and guiltless have suffered death, harm, oppression, injury, and infamy”. This shows how the Inquisition gained its fearful reputation, but maybe with innocent people dying for it.Another problem was that the definition of heresy was quite loose and it found it hard to stick to one set of rules. Therefore, it made it easier for the Inquisition to convict people of heresy as they could shift the boundaries. The evidence provided by the Inquisition usually showed the potential rather than actual incidents of Judaism.Also the Inquisition never named the informer, so this provided the opportunity for the settling of old quarrels or disputes between neighbours. This usually involved sins n people’s daily lives like blasphemy and sexual misconduct.A consequence of the reintroduction of the Inquisition into Spain came through the treatment of the conversos. Because of the way they had been treated, the focus turned onto the Jews, and they quickly became scapegoats as the Spanish people’s anger was directed onto them. Dislike of the Jews grew quickly and the ‘convivencia’ couldn’t be sustained for much longer.This led to extreme measures, Jewish areas were walled off and they were made to wear yellow badges. This eventually led to the expulsion of the Jews in 1482 (wasn’t official until 1492) and they were given four months to convert or leave.The reintroduction of the Inquisition was important, as it led to major changes within Spain. It also caused a big shake up, one reason being because it came under Isabella and Ferdinand’s control. It can be said that they used it like their own personal secret police and used the office for their own gain. It struck fear into the Spanish people, and is probably one the reasons why Protestantism failed to grab hold in Spain.