Yitzhak Sadeh (, born Isaac Landsberg in Lublin, Russian Empire in 1890, died Tel Aviv, Israel in 1952), was the commander of the Palmach, one of the founders of the Israel Defense Forces at the time of the establishment of the State of Israel and a cousin of British philosopher Isaiah Berlin.He was honored with a medal from the Russian army for his bravery during World War I. During 1917-1919, he assisted Joseph Trumpeldor in the founding of Hahalutz (The Pioneer) movement. In 1920, Sadeh became an oleh by making aliya to Eretz Israel. where he became one of founders and leaders of Gdud Ha'avoda (The Work Battalion).
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