Since the existence of the earliest Jewish diaspora, many Jews have aspired to return to "Zion" and the "Land of Israel", though the amount of effort that should be spent towards such an aim was a matter of dispute. The hopes and yearnings of Jews living in exile are an important theme of the Jewish belief system. After the Jews were expelled from Spain in 1492, some communities settled in Palestine. During the 16th century, Jewish communities struck roots in the Four Holy Cities—Jerusalem, Tiberias, Hebron, and Safed—and in 1697, Rabbi Yehuda Hachasid led a group of 1,500 Jews to Jerusalem. In the second half of the 18th century, Eastern European opponents of Hasidism, known as the Perushim, settled in Palestine.