Complex sentence: The kibbutz was established in June 1948 by a group of idealistic Zionists who settled in the Arab village of al-Tantura, the residents of which having been expelled by Jewish forces only a few weeks earlier.
Split into simpler sentences: The kibbutz was established in June 1948 by a group of idealistic Zionists who settled in the Arab village of al-Tantura. The Arab residents had been expelled by Jewish forces only a few weeks earlier.