The first traces of Islam in the Netherlands date back to the 16th century. Ottoman and Persian traders settled in many Dutch and Flemish trading towns, and were allowed to practice their faith, although most of them belonged to the Jewish or Greek Orthodox community under the Sultan. The English traveler Andrew Marvell referred to the Netherlands as "the place for Turk, Christian, heathen, Jew; staple place for sects and schisms" due to the religious freedom and the large number of different religious groups there. References to the Ottoman state and Islamic symbolism were also frequently used within 16th century Dutch society itself, most notably in Protestant speeches called "hagenpreken", and in the crescent-shaped medals of the Geuzen, bearing the inscription "Rather Turkish than Papists". When Dutch forces broke through the Spanish siege of Leiden in 1574, they carried with them Turkish flags into the city. During the Siege of Sluis in Zeeland in 1604, 1400 Turkish slaves were freed by Maurice of Orange from captivity by the Spanish army. The Turks were declared free people and the Dutch state paid for their repatriation. To honor the resistance of the Turkish slaves to their Spanish masters, Prince Maurice named a local embankment "Turkeye". Around this time the Netherlands also housed a small group of Muslim refugees from the Iberian peninsula, called Moriscos, who would eventually settle in Constantinople.