The coronation of Philip II as king of Portugal at Tomar on 16 April 1581 created the first empire upon which the sun never set. Nevertheless, the king did not look forward to the ceremony: ‘As you know’, he confided in a letter to his daughters, ‘they want to dress me in silk brocade, very much against my will’; but, on that historic day, he rose to the occasion. Putting aside the mourning that he had worn since the death of his fourth wife, six months before, ‘The king came in clothed in silk robes of crimson, with a long train… Crowned, with the sceptre in his hand, he looked like King David.’

Philip's accession to the throne had already been announced to the outposts of the Portuguese empire: thus in November 1580 the king ordered the city of Goa to obey his orders thenceforth, and the governor proclaimed him in September 1581, sending on news to Malacca, the Moluccas and other distant territories. The only resistance to the Spanish succession arose in the Azores, but amphibious expeditions conquered first São Miguel in 1582 and then, with a force of ninety-eight ships and 15,000 men, Terceira in 1583. Philip's possessions now ran from Madrid through Mexico, Manila, Macao and Malacca to India, Mozambique and Angola and so back to Madrid.

A practical demonstration of the monarchy's new global reach occurred during the lunar eclipse of 17 November 1584: the newly founded Academy of Mathematics in Madrid sent out in advance a dossier of instructions, including a semi-circle of the same size for recording observations, not only to Antwerp, Toledo and Seville, but also to Mexico City, Manila and perhaps even Macao.