In 1745, a Voyage was ordered by the Spanish Government, to examine the Coast of Patagonia, principally with the design of obtaining communication with the natives, to learn how they were disposed for receiving the light of the Gospel.

For this voyage a frigate named the Sant Antonio, commanded by D. Joachim de Olivarez, was sent from Spain, first to Buenos Ayres. A Jesuit named Josef de Quiroga, who had many years, previous to his entrance into the Holy Order, followed the profession of a mariner, embarked in the Sant Antonio on this expedition, at the express desire of the Catholic King, and he was especially charged with the care of making observations. The distance of time is much too great for this Josef de Quiroga to be the person of that name who, in 1680, desolated the Ladrone Islands. Other Fathers of the same Order were joined to Quiroga at Buenos Ayres, one of whom, Thomas Falkner, a native of Great Britain or of Ireland, afterwards published in England, A Description of Patagonia, and the adjoining parts of South America. The instructions given to those entrusted with this expedition directed them to make a settlement at Port San Julian. On the 17th of December 1745, the Sant Antonio sailed out of the Rio de la Plata.