Moctezuma was already a prisoner of Cortés in Tenochtitlan, the people of Ecatepec accepted him as their ruler and hid him along with his mother.

After the fall of Tenochtitlan, he was one of the five Aztec lords held captive by Cortés along with Cuauhtemoc, the cihuacohuatl Tlacotzin, Oquiztzin, and Motelchiuhtzin.

He was spared from execution when Cuauhtemoc was hanged by Cortés along with Tetlepanquetzatzin, tlatoani of Tlacopan and don Pedro Cohuanacochtzin.

As the grandson of a former Tlatoani, in the year 7 Tochtli (1538), he was chosen as the first governor of Tenochtitlan (Mexico), by the don Antonio de Mendoza, first viceroy of México.

[2] Through Doña Juana de Alvarado, Don Diego de Alvarado Huanitzin is among the royal ancestors of the Guerrero-Dávila-Moctezuma, a prominent noble family during the Viceroyalty of the New Spain and whose descendants are still present today in Mexico City.