Cortés himself had expected to be made the permanent ruling crown official of New Spain, since he had led the Spanish conquest of the Aztec Empire.

[3] Mendoza's status as a noble and his family's loyalty to the Spanish crown made him a suitable candidate for appointment.

[4] Don Antonio and Bishop Juan de Zumárraga were key in the formation of two institutions of Mexico: the Colegio de Santa Cruz at Tlatelolco (1536), where the sons of Aztec nobles studied Latin, rhetoric, philosophy and music, and the Royal and Pontifical University of Mexico (1552), modeled on the University of Salamanca, which trained young men for the Catholic Church.

Also under his instructions, the first printing press in the New World was brought to Mexico in 1539, by printer Juan Pablos (Giovanni Paoli).

[5] In reaction to the crisis caused by the New Laws, Mendoza introduced the policy of obedezco pero no cumplo ("I obey but do not comply"), which means "I respect the authority of the crown, but in my judgment I do not implement particular legislation."

[6] In 1542 an insurrection of the Indians, called the Mixtón Rebellion threatened to push the Spaniards out of northwestern Mexico, bringing the area under indigenous control.

By the viceroy's order men, women and children were seized and executed, some by cannon fire, some torn apart by dogs, and others stabbed.

During his term of office, Mendoza is credited with consolidating the sovereignty of the Crown throughout the Spanish conquests in New Spain and limiting the power and ambition of the first conquistadors.