structural:expansion, linguistic:voice_change
Appointment to governorship of Mexico and internal dissensions

Many historical sources have conveyed an impression that Cortés was unjustly treated by the Spanish Crown, and that he received nothing but ingratitude for his role in establishing New Spain. This picture is the one Cortés presents in his letters and in the later biography written by Francisco López de Gómara. However, there may be more to the picture than this. Cortés's own sense of accomplishment, entitlement, and vanity may have played a part in his deteriorating position with the king:

Cortés personally was not ungenerously rewarded, but he speedily complained of insufficient compensation to himself and his comrades. Thinking himself beyond reach of restraint, he disobeyed many of the orders of the Crown, and, what was more imprudent, said so in a letter to the emperor, dated October 15, 1524 (Ycazbalceta, "Documentos para la Historia de México", Mexico, 1858, I). In this letter Cortés, besides recalling in a rather abrupt manner that the conquest of Mexico was due to him alone, deliberately acknowledges his disobedience in terms which could not fail to create a most unfavourable impression.

King Charles appointed Cortés as governor, captain general and chief justice of the newly conquered territory, dubbed " New Spain of the Ocean Sea". But also, much to the dismay of Cortés, four royal officials were appointed at the same time to assist him in his governing—in effect, submitting him to close observation and administration. Cortés initiated the construction of Mexico City, destroying Aztec temples and buildings and then rebuilding on the Aztec ruins what soon became the most important European city in the Americas.

Cortés managed the founding of new cities and appointed men to extend Spanish rule to all of New Spain, imposing the encomienda system in 1524. He reserved many encomiendas for himself and for his retinue, which they considered just rewards for their accomplishment in conquering central Mexico. However, later arrivals and members of factions antipathetic to Cortés complained of the favoritism that excluded them.

In 1523, the Crown (possibly influenced by Cortés's enemy, Bishop Fonseca), sent a military force under the command of Francisco de Garay to conquer and settle the northern part of Mexico, the region of Pánuco. This was another setback for Cortés who mentioned this in his fourth letter to the King in which he describes himself as the victim of a conspiracy by his archenemies Diego Velázquez de Cuéllar, Diego Columbus and Bishop Fonseca as well as Francisco Garay. The influence of Garay was effectively stopped by this appeal to the King who sent out a decree forbidding Garay to interfere in the politics of New Spain, causing him to give up without a fight.