Hamburg was one of the cities to take in Huguenots. Read a historical account here:
Between 1572 and 1588 many Huguenots came from France and the Netherlands to Hamburg. They did not have the privilege to spread their religion within the city walls. The Earl of Holstein-Pinneberg granted them to build churches in Kleine Freiheit. Here they heard sermons in French, Dutch and German. Because of language problems a separation within the parish was ordered. In 1716 the Hamburg parish was separated from the Altona parish and from the Hamburg parish the French speaking parish separated in 1761. The Hamburg senate issued religious freedom in 1785 which was fully recognized only in 1860.
The records of the Huguenots are housed in the Staatsarchiv Hamburg. The time frame is 1685-1908 and covers births, confirmations, marriages and burials among others.
The first Mennonites came from the Netherland to Hamburg in 1570. At first the newly arrived received preaching privileges in Altona. They were able to build a church. Until 1682 three Mennonite parishes existed simultaneously. From 1726 on the Mennonites employed full-time ministers. Around 1800 the sermons were preached in German. In 1814 the Mennonites received full residental privileges mainly in Altona.
The records of the Mennonites are housed in the Staatsarchiv Hamburg. The time frame covered is 1550 and 1620-1983. The records are varied with vital records among them.