Final answer:
The Codex Mendoza frontispiece served to document Aztec history, including the foundation of Tenochtitlan, its military conquests, and religious significance, providing an overview for Viceroy Mendoza and King Charles I.
Step-by-step explanation:
The function of the Codex Mendoza frontispiece is multifaceted. It primarily served to record information about the Aztec empire for Viceroy Mendoza and, in turn, for King Charles I.
The frontispiece, showcasing The Founding of Tenochtitlan, depicts an eagle on a cactus with a rock in the center, symbolizing the foundation and origins of Tenochtitlan. The corners extending from this central image represent the four corners of the world, indicating the expanse of the Aztec Empire.
Further, the battle scenes at the bottom demonstrate the Aztec military conquests, and the depiction of the Templo Mayor at the top indicates the temple's significance to the Aztec religion and culture. This multifunctional illustration aimed to provide an overview of the Aztec empire.