Buczacz was founded in the 14th century. The following historical description of Buczacz and its Jewish community is derived from Pinkas Hakehollot. Encyclopaedia of Jewish Communities. Poland Vol. II, Eastern Galicia (Jerusalem: Yad Vashem Martyrs' and Heroes' Rememberance Authority, 1990, pp. 83-89 [Hebrew]. The section on Buzcacz was written by Aharon Jakubowicz and Aharon Weiss. Its founders were leading Polish aristocrats, and among its early settlers were Jews, coming to inhabit a predominantly Ukrainian rural milieu. By way of contrast with the mainly Slavic peasant populations, the Jewish settlers in the lands of the eastern Galicia were townspeople and skilled craftsmen. Among them were individuals experienced in trade and finance. Polish kings and princes welcomed the contribution of Jews to the colonization of their eastern realms, and encouraged them to settle and offered them protection. With the unification of Poland and Lithuania in 1569, the newly united kingdom extended from the Baltic to the Black Sea. Owing to its importance as a market town, Buczacz had become a prominent trading centre linking the Poland and the Ottoman Empire.
During Cossack uprisings of the mid-17th century Buczacz successfully defended itself, with Jews joining in the defence of the town. Large numbers of Jewish refugees from the areas laid waste by Chmielnicki and his warring Cossacks sought sanctuary in Buczacz. In 1772 and again in 1775 the town was captured by the Ottoman Turks. Under the leadership of the organized Jewish community, the Kehila, Jews joined with the Poles in its defence.
Following the Turkish wars, the Kehila expanded and prospered. The community established a Beit Midrash (a house of study, later known as the "Old" Beit Midrash) and a Jewish hospital ("Ha-Kodesh") was in existence at the end of the 17th century. Until 1664 the Jews of Buczacz fell under the religious jurisdiction of the Lvov Kehila. In that year Buczacz and other communities seceded and established their own Kehila. A Synagogue was built in Buczacz, designed by an Italian architect. This Synagogue ranked among the most beautiful and famous in the area. Its floor was below ground level with walls five meters thick. It was celebrated for its religious artifacts, around which some popular legends arose.
In 1699 the civil rights of the Jews of Buczacz were reconfirmed, and Jews were permitted to reside anywhere in the town and to pursue any occupation (other than dealing in Christian religious items). The Jewish community was given judicial autonomy (including a tax exemption for three communal properties: the houses of the rabbi and hazzan, and the hospital), and Jews were coopted for the defence of the town. The local guard was composed half of Jews, half of Christians.
The Jewish community of Buczacz flourished during the next century. By the end of the 17th century the Jewish population of the town had expanded to some 1500 families. A local Jew, Abrahamchik, was a partner in the monopoly over imports of tobacco into Poland. Many local Jews joined the Sabbatean messianic movement led by Shabtai Zvi, and a few joined the mystical messianic cult headed by Chaim Moloch. Among the rabbis of Buczacz were R. Ya'akov Moshe from Shrigrad (c. 1648), R. Elchanan ben Ze'ev (author of Bat Yekutiel), R. Moshe from Zholkvah, R. Aryieh-Lev ben Mordecai-Madrish Uerbach (who in 1740 went to Stanislov), R. Meit ben Hirtz (1765-70), R. Zvi Hirsh b'reb Ya'akov Karo, author of Natah Sha'ashueem (1770-1813).