 Ben-Gurion's passion for Zionism, which began early in life, led him to become a major Zionist leader and executive head of the World Zionist Organization in 1946.As head of the Jewish Agency from 1935, and later president of the Jewish Agency Executive, he was the "de facto" leader of the Jewish community in Palestine, and largely led its struggle for an independent Jewish state in Mandatory Palestine.On 14 May 1948, he formally proclaimed the establishment of the State of Israel, and was the first to sign the Israeli Declaration of Independence, which he had helped to write.