Philip did not return to Spain until 1559.
When he did, Philip found a cover story for a Spanish colony in the Philippines. Miguel López de Legazpi (fn) commanded a four-ship expedition to "discover the islands to the west".
Legazpi departed from Mexico towards the end of November 1564, annexed Guam along the way and arrived off the coast of Cebu in mid-February 1565.
Two significant developments ensured Legazpi was there for good.
The first came when Andrés de Urdaneta discovered a viable route between Manila and Acapulco in 1565. Urdaneta left Cebu at the start of June. He found the long-sought westerly winds around 38 degrees and reached Acapulco four months later after travelling twenty thousand kilometres.
With a viable route in both directions, the other thing the Spanish needed was a suitable headquarters.
Legazpi identified an easily defensible site, with an excellent sheltered harbour next door to the rice bowl on Luzon's Central Plain at Maynila. It was already the most important centre in the islands when Legazpi made his first diplomatic approach in May 1570.
While his first attempt to secure his prefered base failed, a second expedition took possession of Maynila on 19 May 1571. After fighting off counter-attacks, Legazpi simplified the spelling and gave the Spanish their headquarters for the next four hundred and twenty-odd years.