Jerónimo de Ortal is mentioned for the first time as a participant in Diego de Ordáz's entrada on the Rio Orinoco. He took part in this venture as an officer and treasurer (tesorero) and was one of Ordáz's closer confidants. It is therefore likely that he - like his intimate Alonso de Herrera - had already participated as a retainer of Ordáz in the conquest of Mexico under Hernán Cortés. During the voyage along the Orinoco River, which lasted from 1531 to 1532, Europeans explored for the first time the hinterland of the coastal region that today belongs to Venezuela and was called Paria by the natives. After the death of Diego de Ordáz, Alonso de Herrera and Jerónimo de Ortal sought the governorship of the province of Paria. While Herrera was provisionally appointed governor of Paria by the Audiencia Real in Santo Domingo, Ortal went to court in Spain.