Complex sentence: The group repelled a vastly superiour Syrian force which overrun the Israeli positions in the first days of the war, in the Golan Heights region of northern Israel, in a battle which proved to be one of the turning points of the war.
Split into simpler sentences: The group repelled a vastly superiour Syrian force which overrun the Israeli positions in the first days of the war, in the Golan Heights region of northern Israel. The battle proved to be one of the turning points of the war.