Page "History of Paraguay" Paragraph 14

After Mendoza returned unexpectedly to Spain, two other members of the expedition -- Juan de Salazar de Espinosa and Gonzalo de Mendoza -- explored the Río Paraguay and met up with Irala.

Leaving him after a short time, Salazar and Gonzalo de Mendoza descended the river, stopping at a fine anchorage.

They commenced building a fort on August 15, 1537, the date of the Feast of the Assumption, and called it Asunción ( Nuestra Señora Santa María de la Asunción ).

Within 20 years, the settlement had a population of about 1, 500.

Transcontinental shipments of silver passed through Asunción on their way from Peru to Europe.

Asunción subsequently became the nucleus of a Spanish province that encompassed a large portion of southern South America — so large, in fact, that it was dubbed " La Provincia Gigante de Indias ".

Asunción also was the base from which this part of South America was colonized.

Spaniards moved northwestward across the Chaco to found Santa Cruz in Bolivia ; eastward to occupy the rest of present-day Paraguay ; and southward along the river to refound Buenos Aires, which its defenders had abandoned in 1541 to move to Asunción.