At its height, the Spanish Inquisition had up to 21 tribunals across the Spanish Empire. These regional courts operated below the Suprema, the central council that coordinated policy and handled appeals and important cases.
The network developed gradually rather than appearing all at once. Early permanent tribunals were established in Castile at Seville and Córdoba in 1482, followed by Toledo, Llerena, Valladolid, Murcia and Cuenca. Other courts were later created in places including the Canary Islands, Logroño, Granada and Santiago de Compostela. The Crown of Aragon had tribunals in Zaragoza, Valencia, Barcelona and Mallorca.
The figure 21 generally refers to the maximum imperial network, not to 21 courts operating simultaneously in mainland Spain alone. Overseas expansion added tribunals at Lima and Mexico City in 1569, and Cartagena in 1610. That distinction explains why smaller figures sometimes appear in summaries: historians may count only Spanish mainland tribunals, only permanent courts at a particular date, or the broader imperial system.