Shas (Hebrew: ש״ס, an acronym for שומרי ספרד Shomrei Sfarad, lit., "(Religious) Guardians of the Sephardim") is an ultra-Orthodox religious political party in Israel. Founded in 1984 under the leadership of Rabbi Ovadia Yosef, a former Israeli Sephardi chief rabbi, who remained its spiritual leader until his death in October 2013, it primarily represents the interests of Haredi Sephardic and Mizrahi Jews.
Originally a small ethnic political group, Shas is currently Israel's seventh-largest party in the Knesset. Since 1984, it has almost always formed a part of the governing coalition, whether the ruling party was Labor or Likud. As of 2017, Shas members currently sit with Likud in the government. SOURCE: Wikipedia