His grandfather, Diego Arias de Ávila, was chief comptroller and a key adviser to King Enrique IV; his older brother was the Count of Puñonrostro; and his uncle was the Bishop of Segovia, a wealthy man who left Pedrarias a fortune.

Physically imposing and athletic, he was nicknamed "the jouster" for his skill in tournaments and "the gallant" in reference to his extravagant wardrobe and spendthrift habits.

[4][better source needed] In 1514, at the age of nearly seventy, he was made commander by King Ferdinand II of Aragon of the largest Spanish expedition (19 vessels and 1,500 men) hitherto sent to America.

Arias Dávila superseded him and promised him his daughter in wedlock but he had Balboa judicially murdered at age 44 on 15 January 1519,[5]: 15  being thus a potential bridegroom but never a son-in-law.

Arias Dávila's daughter was known as "María de Peñalosa" to honor her female ancestors, something by no means uncommon between the High Spanish Nobility at the time.

Another of Arias Dávila's daughters, who was born when he was elderly, Isabel Arias or Isabel de Bobadilla (to mark the female ancestors of the family), was married in Valladolid, Spain, 1537, to his loyal lieutenant Hernando de Soto, the successful conquistador and explorer of Florida and Mississippi and Governor of Cuba.

Moreover, he was a party to the original agreement with Francisco Pizarro and Diego de Almagro which brought about the discovery of Peru, but he withdrew (1526) for a small compensation, having lost confidence in the outcome.