Year 1539 (MDXXXIX) was a common year starting on Wednesday (link will display the full calendar) of the Julian calendar.

Hernando de Soto (c.1496/1497–1542) was a Spanish explorer and conquistador who, while leading the first European expedition deep into the territory of the modern-day United States, was the first European documented to have crossed the Mississippi River.

A vast undertaking, de Soto's North American expedition ranged throughout the southeastern United States searching for gold and a passage to China. De Soto died in 1542 on the banks of the Mississippi River in Arkansas or Louisiana.

Hernando de Soto was born to parents who were hidalgos of modest means in Extremadura, a region of poverty and hardship from which many young people looked for ways to seek their fortune elsewhere. Two towns—Badajoz and Barcarrota—claim to be his birthplace. He spent time as a child at each place, and he stipulated in his will that his body be interred at Jerez de los Caballeros, where other members of his family were interred. The age of the Conquerors came on the heels of the Spanish reconquest of the Iberian peninsula from Islamic forces. Spain and Portugal were filled with young men seeking a chance for military fame after the Moors were defeated. With discovery of new lands to the west (which they thought at the time to be East Asia), the poor young men were attracted to whispers of glory and wealth.