The Old Yishuv, the Jewish communities in the Ottoman period, was composed of how many clusters?

The Old Yishuv were the Jewish communities of the southern Syrian provinces in the Ottoman period, up to the onset of Zionist aliyah and the consolidation of the New Yishuv by the end of World War I. As opposed to the later Zionist aliyah and the New Yishuv, many Jews of the Old Yishuv, whose members had continuously resided in or had come to Eretz Yisrael in the earlier centuries, were largely religious Jews, who depended on external donations (Halukka) for financial support.

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'arabim who settled in Eretz Yisrael in the late Mamluk and early Ottoman periods. A second group was composed of Ashkenazi Hassidic Jews who had emigrated from Europe in the 18th and early 19th centuries. A third wave consisted of Yishuv members who arrived in the late 19th century. The Old Yishuv was thus generally divided into two independent communities – the Sephardim (including Musta'arabim), mainly consisting of the remains of Jewish communities of Galilee and the four Jewish holy cities, which had flourished in the 16th and 17th centuries; and the Ashkenazim, whose immigration from Europe was primarily since the 18th century.