Cristóvão da Gama (son of the legendary Portuguese explorer Vasco da Gama) had some decades earlier, in 1541, led a military expedition to save the Ethiopian emperor Gelawdewos from the onslaught of Ahmed Gragn, a Muslim Imam who almost destroyed the existence of the Ethiopian state.

The Jesuits who had accompanied or followed the expedition into Ethiopia, and fixed their headquarters at Fremona (near Adwa), have been oppressed and neglected over the past six decades, but not actually expelled.

Father Pedro Páez, born in Olmeda de las Cebollas (now Olmeda de las Fuentes, near Madrid), had studied at Coimbra and, sent from Goa to Ethiopia as a missionary in 1589, had been held captive in Yemen for seven years, from 1590 to 1596, where he had used his time to learn Arabic.

During this period he had to travel through the Hadramaut and Rub'al Khali deserts, and tasted coffee in Mocha, being most probably the first European to undergo such experiences.

Finally arriving at Massawa in 1603, he had proceeded to Debarwa where he met the chief of the Portuguese in Ethiopia, John Gabriel, on May 11, and four days later had made his way to Fremona.Unlike his predecessor, Andre de Oviedo, Paul Henze describes Paez as "gentle, learned, considerate of the feelings of others".

When summoned to the court of the young negusä nägäst Za Dengel, his knowledge of Amharic and Ge'ez, as well as his knowledge of Ethiopian customs impresses the sovereign so much that Za Dengel decides to convert from the Coptic Tewahido Church to Catholicism —although Páez, a man of great tact and judgment, warns him not to announce his declaration too quickly.

However, when Za Dengel proclaims changes in the observance of the Sabbath, Páez retires to Fremona, and waits out the ensuing civil war that ends with the emperor's death.