a separate group by Statistics Netherlands, concentrating in specific neighborhoods especially in Nieuw-West, Zeeburg, Bijlmer and in certain areas of Amsterdam-Noord. In 2000, Christians formed the largest religious group in the city (28% of the population). The next largest religion was Islam (8%), most of whose followers were Sunni. In 2015, Christians formed the largest religious group in the city (28% of the population). The next largest religion was Islam (7.1%), most of whose followers were Sunni. Religion In 1578, the largely Catholic city of Amsterdam joined the revolt against Spanish rule, late in comparison to other major northern Dutch cities. Catholic priests were driven out of the city. Following the Dutch takeover, all churches were converted to Protestant worship. Calvinism was declared the main religion; although Catholicism was not forbidden and priests allowed to serve, the Catholic hierarchy was prohibited. This led to the establishment of schuilkerken, covert religious buildings that were hidden in pre-existing buildings. Catholics, some Jewish and dissenting Protestants worshiped in such buildings. A large influx of foreigners of many religions came to 17th-century Amsterdam, in particular Sefardic Jews from Spain and Portugal, Huguenots from France, Lutherans, Mennonites, as well as Protestants from across the Netherlands. This led to the establishment of many non-Dutch-speaking churches. In 1603, the Jewish received permission to practice their religion in the city. In 1639, the first synagogue was consecrated. The Jews came to call the town 'Jerusalem of the West'. As they became established in the city, other Christian denominations used converted Catholic chapels to conduct their own services. The oldest English-language church congregation in the world outside the United Kingdom is found at the Begijnhof. Regular services there are still offered in English under the auspices of the Church of Scotland. Being Calvinists, the Huguenots soon integrated into the Dutch Reformed Church, though often retaining their own congregations. Some, commonly referred by the moniker 'Walloon', are recognizable today as they offer occasional services in French. In the second half of the 17th century, Amsterdam experienced an influx of Ashkenazim, Jews from Central and Eastern Europe. Jews often fled the pogroms in those areas. The first Ashkenazis who arrived in Amsterdam were refugees from the Khmelnytsky Uprising occurring in Ukraine and the Thirty Years' War, which devastated much of Central Europe. They not only founded their own synagogues, but had a strong influence on the 'Amsterdam dialect' adding a large