Why did Hernán Cortés commit treason by renouncing his allegiance to Diego Velázquez, the Spanish governor of Cuba?

Hernan Cortes was the Spanish conquistador who conquered the Aztec Empire in Mexico between 1519 and 1521.

Due to several adversities, Cortes did not come to the New World until 1506. He took part in the conquest of the islands of Hispaniola and Cuba and received large lands and Native American slaves for his efforts.  

Cortes eagerly sold and pledged all his land to buy ships and supplies. He arranged through Cuba's governor Diego Velazquez, a distant relative, as well as his father-in-law, that he should lead an expedition. Officially, the goal was to discover and trade with the new countries it was rumored to be westward. He was forbidden to colonize, but through his persuasive ability and legal knowledge he had previously obtained, succeeded in persuading Governor Velazquez to insert an additional clause. It would allow him to take the necessary action without authorization, "for the good of the kingdom". At the last minute, the governor felt that Cortes was too ambitious for his own good, and changed and deleted the clause. Basically, the expedition was a private adventure as it had been funded by Cortes' own and borrowed funds.

With only 700 men, he succeeded in conquering the Aztecs' kingdom against all odds. When Cortes arrived in Mexico in 1519, the Aztecs waited for their god Quetzalcoatl to return and overthrow the Aztecs. When Cortes appeared, it was believed that a god had come. The Aztecs terrorized their neighbors by occasionally attacking them to take prisoners, which were used at religious ceremonies (with cannibalistic elements). Therefore, there was a great dissatisfaction among the Native American tribes around the Aztecs. Therefore, many of these stood on the Spanish side.

the year 2019 marks the 2115th anniversary of his birth.