Was the persecution of heresies a way of ecclesiastical defense of their dogmas and knowledge? How many types of heresies existed? Why were the Jews harassed more viciously than the Moors? Valencia is today the city of light, sea and sun... but it was not always so. Darkness took over the cordial hospitality that characterized this land, which has always been, and still is, a melting pot of religions and cultural, social and economic exchange between different peoples. Muslims, Christians and Jews coexisted peacefully, honoring and respecting the rites of each of their faiths and having their own spaces within the city. However, everything would change radically when the Catholic Monarchs ascended to the throne and imposed, without hesitation, the institution of the Holy Inquisition throughout the national territory. The Crown of Aragon did not give in easily and defended until the end that the executing arms of the Inquisition did not reach the Kingdom, but finally succumbed to threats, extortion and non-compliance with the Fueros. Thus began a battle without quarter, with the gears of the inquisitorial machinery set in motion to carry out the greatest persecution, condemnation and execution that our history has known. The Tribunal of the Holy Office of Valencia stood out as one of the most bloodthirsty of all those that existed.