The Old Yishuv developed after a period of severe decline in Jewish communities of the Southern Levant during the early Middle Ages, and was composed of three clusters. The oldest group consisted of the Ladino-speaking Sephardic Jewish communities in Galilee and the Judeo-Arabic speaking Musta'arabi Jews who settled in Eretz Yisrael in the Ottoman and late Mamluk period. A second group was composed of Ashkenazi and Hassidic Jews who had emigrated from Europe in the 18th and early 19th centuries. A third wave was constituted by Yishuv members who arrived in the late 19th century. The Old Yishuv was thus generally divided into two independent communities – the Sephardi Jews (including Musta'arabim), mainly constituting the remains of Jewish communities of Galilee and the Four Holy Cities of Judaism, which had flourished in the 16th and 17th centuries; and the Ashkenazi Jews, whose immigration from Europe was primarily since the 18th century.