Hernan Cortes strategically defeated the Aztec empire, one of the most powerful and brutal indigenous groups in Mexico. His conquest brought Mexico under Spanish rule and secured an abundance of gold for Spain's monarch, King Charles. Cortes planned and oversaw the building of Mexico City, the country's modern capital, and opened the door to further conquest in Latin America.
Cortes' foray into Aztec territory began when he defied orders from his superior in Cuba and set sail for Mexico with 500 men. Despite limited forces, Cortes won native allies while marching toward the Aztec capital Tenochtitlan; many subjugated tribes resented the harsh rule and steep taxes the Aztecs imposed and were willing to join with Cortes. The Tlaxacan people were Cortes' primary supporters, providing the Spaniards with 5,000 men as protection when entering territory belonging to Aztec allies. After several failed attempts to convince Emperor Montezuma to submit to Spanish and Christian authority, Cortes took the Aztec leader hostage.
Cortes secured another small force by attacking the Spanish leaders sent to Mexico to arrest him for insubordination and persuading many lower-ranking soldiers to join him. Although a violent rebellion and Montezuma's death drove the Spanish from Tenochtitlan for a year, Cortes led a successful assault on the Aztecs in 1521. His success was partially due to significant Aztec deaths from smallpox. One of Cortes' men also devised ships that were assembled quickly on-site, helping the Spanish blockade the lake surrounding Tenochtitlan.