Protector de Indios
The office charged with defending the Indians in the colonial courts. By 1591 every city with an Audiencia was to have a salaried lawyer and a procurator to run the Indians' lawsuits, forbidden to take a fee from them; in New Spain the service was paid for by a half-real levy. The same laws that built it also record, in the crown's own words, that the officials paid to defend the Indians were fleecing them.
Why this wins its question: The usual English account of the protector de indios is a sentence — a colonial official supposed to look after the Indians, generally ineffective — with no text behind it. Read in the code itself, the office is far more specific and far more interesting: a state-salaried lawyer and procurator at every Audiencia, statutorily barred from charging the people he represented, funded in New Spain by a named half-real levy, protected against arbitrary dismissal, closed to mestizos, and — in the crown's own 1623 wording — routinely extorting the litigants it existed to defend. Every one of those is quoted here from a digitised printing opened page by page, with the monarch, place and date the compilers printed in the margin.
Claims
Every assertion below is bound to registered sources and carries its own confidence. Weight them; do not treat the page as uniformly authoritative.
The office was abolished and then restored. Recopilación libro VI, título 6, ley j — Philip II, Madrid, 10 January 1589 — records that earlier orders had directed the Protectores y Defensores de los Indios to be suppressed, that "en cuya execucion se han experimentado grandes inconvenientes", and therefore commands that they may exist again, to be chosen afresh by the viceroys and president-governors in the provinces where they had been, of competent age, and to exercise their offices with "la christiandad, limpieza, y puntualidad, que son obligados, pues han de amparar y defender á los Indios".
Ley iij of the same título — Philip II, 9 April 1591, and Philip III at Ventosilla, 17 October 1614 — orders that in every city where there is an Audiencia the viceroy or president appoint a letrado and a procurador "que sigan los pleytos, y causas de los Indios, y los defiendan", with a competent salary charged to the penas de estrados or to community funds, and rules that "en ningun caso puedan llevar derechos": the Indians' advocates were paid by the state and prohibited from charging their clients.
In New Spain the service had a dedicated revenue. Ley iiij — Philip IV, Madrid, 13 June 1623 — states that "cada Indio de la Nueva España paga medio real, que se distribuye en salarios de Asesores, Relatores, Escribanos de Cámara, y Gobernacion, Letrados, Procuradores, Solicitadores, y otros Ministros, por los pleytos y negocios, que tienen en el Gobierno, Audiencia, y otros Tribunales": a half-real head levy funding a standing legal service for indigenous litigants.
That same law exists because the service was being abused, and says so. It continues that notwithstanding the salaries "hay grande exceso en llevarles mayores cantidades, y presentes, y los detienen, y retardan, con mucho agravio, y vexacion", and orders the viceroys and Audiencias of New Spain, Peru and the other provinces to remedy it, to enforce the laws, to allow no further charges, and to punish the guilty. The crown's own text is the best evidence against a triumphalist reading of the institution.
The office carried tenure protection: ley v — Philip III, 4 July 1620 — forbids viceroys and presidents to remove or dismiss the protectores generales once elected except for legitimate, certain cause examined by the Audiencia. A protector who could be removed at will was of little use, and the rule implies he was under pressure.
The office was also closed by descent. Ley vij — Philip II, Madrid, 20 November 1578 — orders viceroys and presidents that when appointing Protectores de Indios "no elijan á Mestizos, porque asi conviene á su defensa, y de lo contrario se les puede seguir daño, y perjuicio". Protection of the Indians and exclusion of the mixed-descent population were written into the same title.
The design was adjusted where it failed in practice. Ley viij — Philip II, in a letter from Madrid of 17 January 1593 — records that the protectoría of the Philippine Indians had been entrusted to the bishops, that they were found unable to attend to "la solicitud, autos, y diligencias judiciales, que requieren presencia personal", and therefore orders the president-governors to name a Protector y Defensor with a salary prorated from the tributes, while declaring that this did not remove the bishops' general superintendence and protection of the Indians.