The history of the Jewish community, founded in the 12th century, follows the same tragic pattern as that in Spain. Jews enjoyed many privileges and high offices in the state, until they were subjected to forced baptism and finally expulsion in 1496. Jews had complete charge of their affairs. They were governed by the chief rabbis, to whom the state delegated much authority. For this privilege they had to pay various taxes, including a degrading poll-tax. Among the notable Jews who served the king were Don Isaac Abravanel and the astronomer Abraham Zacuto, whose astrolabe, the forerunner of the modern sextant, was used by the explorer Vasco da Gama. With their expulsion from Spain in 1492, many Jews found refuge in Portugal. But here, too, tragedy would soon overtake them. King Manoel, though friendly at first, agreed to their expulsion as part of a marriage bargain he entered into with Ferdinand and Isabella of Spain. The Spanish rulers insisted that Manoel’s marriage to their daughter be conditional on the expulsion of Jews from Portugal. The expulsion order, promulgated in 1496, permitted Jews to take all their property, but ordered the baptism of all young people. However, even the adults brought to Lisbon were not allowed to leave; they were offered the choice of being sold as slaves or baptized. Many who were baptized secretly clung to their faith as Marranos. In 2007 there were 500 Jews in Portugal. Engaged mainly in the textile trade, they are concentrated in Lisbon and Oporto.