In this letter, Cortes portrays Moctezuma as a powerful, dazzlingly wealthy monarch—one who commands extraordinary wealth. He describes how Moctezuma greets him flanked by noble attendants who kiss the ground before him and how the king made gifts to him of gold and silver. But he also recounts a speech that Moctezuma made in which he offers the conquistador his fealty and acknowledges that Charles V is their "natural sovereign." Cortes emphasizes the efforts he made to convert the people of Tenochtitlan to Christianity by appealing to the king, stressing the bloody human sacrifices they made after successful battles.

In short, Cortes wants to emphasize the power and majesty of the Aztec monarch at the time when the conquistador was staking his claim to the riches of the city. The letter was written in 1520, and less than a year after it reached Spain, Moctezuma was dead, having been killed in a civil war involving various Aztec factions as well as many of the surrounding peoples that had long resented their rule.

This letter, written from a conquistador to his sovereign, is intended to promote Cortes himself, to stake his claim to sole leadership of Mexico, and to make him accountable to nobody but the Spanish king.