Short answers, pulled from the story.
Pope Sixtus IV authorized the Spanish Inquisition in 1478 with the bull Exigit sincerae devotionis affectus. The first two inquisitors, the Dominicans Miguel de Morillo and Juan de San Martín, were appointed on the 27th of September 1480 by King Ferdinand II of Aragon and Queen Isabella I of Castile.
The Spanish Inquisition prosecuted an estimated 150,000 people over its history. Of these, an estimated 3,000-5,000 were executed, mostly by burning at the stake, with executions concentrated in the initial decades between 1480 and 1530.
Tomás de Torquemada was a Dominican friar who served as confessor to Ferdinand and Isabella before being appointed Inquisitor General of Aragon, Catalonia, and Valencia by Pope Sixtus IV on the 17th of October 1483, uniting all Spanish inquisitorial activity under a single leader. He established the Inquisition's formal trial procedures in 1484 with a 28-article code that remained largely unchanged for over three centuries, and he persuaded the monarchs to issue the 1492 Alhambra Decree expelling all Jews from Spain.
The Alhambra Decree of 1492 ordered all Jews, regardless of age, to leave Spain and never return, under penalty of death and property confiscation. Joseph Pérez estimates that between 50,000 and 100,000 Jews were expelled. The decree was not rescinded until the 16th of December 1968, when Francisco Franco revoked it following the Second Vatican Council's rejection of Jewish deicide.
Limpieza de sangre, or blood purity statutes, were laws targeting Jewish and Muslim converts to Christianity that introduced race-based discrimination and antisemitism. Toledo enacted the first statute in 1449, barring conversos and their descendants from holding public office or testifying in court. In 1593, the Jesuits adopted the Decree de genere, barring anyone with any Jewish or Muslim ancestry from the Society of Jesus. These statutes persisted in some areas into the 19th century, and in Mallorca no Xueta priests could perform Mass in a cathedral until the 1960s.
The Spanish Inquisition was permanently abolished on the 15th of July 1834 by regent Maria Christina of the Two Sicilies, with approval from Cabinet President Francisco Martínez de la Rosa. The last execution carried out under its authority was that of schoolteacher Cayetano Ripoll, hanged on the 26th of July 1826 in Valencia for teaching deist principles.