Although twenty years separate the events, Columbus' westward voyage across the Atlantic and the initial Portuguese expedition to the Moluccas combined to bring the Spanish into the narrative surrounding The Portuguese Question.
While The Critical Reader might question the connection, it works like this.
Columbus' voyage resulted in the Papal ruling that redrew the border between the Spanish and Portuguese spheres of influence. The horizontal north-south division along a parallel south of the Canary Islands changed to a line drawn along a meridian running down the middle of the Atlantic.
That meridian was moved further west under the Treaty of Tordesillas, delivering Brazil into the Portuguese hemisphere. Naturally, the treaty pushed the antimeridian, which had to lie somewhere east of China, further west.
Calculating longitude was an inexact science, and the circumference of the globe was yet to be determined. Still, the antimeridian was always going to be somewhere near the Moluccas.
Aside from prompting the papal ruling, Columbus also brought Spain into the Americas.
So Cortes conquered Aztec Mexico, and Pizarro overthrew the Incas. Both conquests allowed Spain to develop ports on the east side of the Pacific.
That became an important consideration when the Spanish crown sent rescue missions to recover a handful of survivors from Magellan's voyage to the Indies.
So, in establishing a context for the voyage that took Torres through the strait to the north of Australia, we need to go back to Fernão de Magalhães, born into a wealthy Portuguese family around 1480.