The Zionist Organization/The Jewish Agency for Palestine/Israel-Central Office, London (Z4)

The World Zionist Organization (WZO), was founded as the Zionist Organization (ZO; 1897–1960) at the initiative of Theodor Herzl at the First World Zionist Congress, which took place in August 1897 in Basel, Switzerland. When it was founded, the goals of the Zionist movement were stated in a resolution that came from that Congress and came to be known as the “Basel Program,” and which set as its chief goals the Jewish settlement of Palestine, the formation of a federation of Jewish organizations at the local and national levels, and the creation and promotion of a Jewish consciousness. The WZO currently consists of the following bodies: The World Zionist Unions, international Zionist federations; and international organizations that define themselves as Zionist, such as WIZO, Hadassah, B'nai B'rith, Maccabi, the International Sephardic Federation, the three streams of world Judaism (Orthodox, Conservative, Reform), delegation from the CIS-Commonwealth of Independent States (some states of the former Soviet Union), the World Union of Jewish Students (WUJS), and more. The Jewish Agency is a parallel organization, with goals, attributes and leadership closely intertwined with those of the Zionist Organization during the years before the establishment of the State of Israel, and to varying degrees after that. Significant changes to the statutes of both organizations occurred in 1952, 1970 and 1979. [Source: Wikipedia]

The Jewish Agency for Israel, previously called The Jewish Agency for Palestine, is the largest Jewish nonprofit organization in the world. Its mission is to "inspire Jews throughout the world to connect with their people, heritage, and land, and empower them to build a thriving Jewish future and a strong Israel."
It is best known as the primary organization responsible for the immigration ("Aliyah") and absorption of Jews and their families from the Diaspora into Israel. Since 1948, the Jewish Agency for Israel has been responsible for bringing 3 million immigrants to Israel,and offers them transitional housing in "absorption centers" throughout the country. The Jewish Agency played a central role in the founding and the building of the State of Israel. David Ben Gurion was the Chairman of its Executive Committee from 1935, and it was in this capacity that on May 14, 1948 he proclaimed independence for the State of Israel. He became Israel's first Prime Minister. In the years before and after the creation of the State, the Jewish Agency oversaw the establishment of about 1,000 towns and villages in Mandate Palestine. It serves as the main link between Israel and Jewish communities around the world. [Source: Wikipedia]