The idea of appointing Crown officials to oversee local affairs was inspired by the late-medieval revival of Roman law.
Their job was to collect taxes, to report to the crown on the state of affairs in the area, and to ensure that royal jurisdiction was not interfered with by members of the church or the nobility.
From 1480 onward, they—and all subsequent Spanish monarchs—never again appointed a noble corregidor and instead relied exclusively on commoners with legal training to fill this office.
After the War of Succession, the new Bourbon kings introduced them into the Aragonese territories, replacing the bailes and vegueres, who, nevertheless, had very similar functions to Castilian corregidores.
The corregidores were given this privileged position either due to having influential families in Spain, or through paying the crown and in return being appointed.
[5] The reformed Audiencia of New Spain began implementing them in the 1530s, but they were not successfully set up in the Viceroyalty of Peru until the administration of Toledo.
The corregidores also served to manage the demands of landowners and merchants, who were eager to take the maximum amounts of profits from indigenous labor.
[5] By law neither corregidores nor governors (nor viceroys, for that matter) could be persons who resided in the district in which they ruled, so that they should not develop ties to the locality, such that they remain disinterested administrators and judges.
Nominally under the viceroys, the long distances from the viceregal and even provincial capitals meant that most corregidores acted independently.
If their district were large enough to require it, they were further assisted by subordinate delegates, called tenientes (lieutenant corregidores).