The strategic objective of the military expedition was to break the trade embargo imposed across the Portuguese Empire, which included Brazil and the East Indies and trading posts in India and China. By securing an alliance with the Portuguese crown, Elizabeth hoped to curb Spanish Habsburg power in Europe and to free up the trade routes to these possessions. That was a difficult proposition because Philip had been accepted as king by the aristocracy and the clergy of Portugal in 1581 at the Cortes of Tomar. The pretender to the throne, António, Prior of Crato, the last surviving heir of the House of Aviz, had failed to establish an effective government-in-exile in the Azores, and turned to the English for support. He was not a charismatic figure, and with his cause compromised by his illegitimacy, he faced an opponent with a relatively strong claim to the throne in the eyes of the Portuguese nobles of the "Cortes", Duchess Catherine of Braganza.