After World War I ended in 1918, Jews began to migrate to Palestine, which was set aside as a British mandate with the approval of the League of Nations in 1922.

After World War I the terms of the Balfour Declaration were included in the mandate for Palestine approved by the League of Nations in 1922. The mandate entrusted Great Britain with administering Palestine and with assisting the Jewish people in “reconstituting their national home in that country.”

Large-scale Jewish settlement and development of extensive Zionist agricultural and industrial enterprises in Palestine began during the British mandatory period, which lasted until 1948. The Jewish community, or Yishuv, increased tenfold during this era, especially during the 1930s, when large numbers of Jews fled Europe to escape persecution by the Nazis. Tel Aviv became the country's largest all-Jewish city, dozens of other towns and villages were founded, and hundreds of Jewish agricultural collectives (kibbutzim) and cooperatives were established.

Many Jewish political parties founded in Eastern Europe as part of the world Zionist movement developed bases in mandatory Palestine. They included labor, orthodox religious, and nationalist groups whose leaders emigrated from Europe and after 1948 became political leaders and officials in the new Jewish state.

The Yishuv extended its institutions after World War I. Among these institutions was an assembly with a National Council that managed the community's day-to-day affairs in education, health, social welfare, and other services. Jewish religious life was supervised by a Rabbinical Council that controlled marriage, divorce, and other family matters. Local government institutions were also developed to run the city of Tel Aviv and many smaller Jewish settlements. The educational system, cultivating Hebrew language and culture, expanded, and the Hebrew University in Jerusalem was founded.

The World Zionist Organization and the Jewish Agency for Palestine assisted the Yishuv by raising funds abroad, recruiting Jewish immigrants, and seeking political support from Western governments.