The Jews of Portugal pre-date the founding of the nation in 1143. When Afonso conquered Lisbon from the Moors in 1147, there already existed thriving Jewish communities in Iberia (Sepharad), perhaps dating as far back as the time of King Solomon. Alfonso welcomed his Jewish subjects and appointed Yahia ben Yahi, the chief rabbi of Santarem, as his treasurer, tax collector, and chief rabbi of the newly formed nation state, Portugal.
Throughout most of the Middle Ages, Portuguese Jews (Sephardim) enjoyed unparalleled freedom, wealth and power. They occupied key positions in government, academia, and commerce, and especially the professions of medicine, science and law. Even when Hebrew was later prohibited, doctors could continue to possess Hebrew books. Places of worship and schools flourished. Jews established the first printing presses in Portugal at Faro, Lisbon and Leiria. The first eleven books printed in Portugal were in Hebrew. The nautical charts of Abraham Zacuto guided Vasco da Gama to India.