The Fourth Aliyah refers to the fourth wave of the Jewish immigration to Israel from Europe and Asia who came based on Zionist motives between the years 1924 and 1928.
Since 1924 the character and the composition of the immigration to the Land of Israel changed, and even though this immigration wave was very close to the previous immigration wave, it has been categorized as separate.
A big immigration wave that began in 1924 and continued during two years, brought a rapid urban development mainly in Tel Aviv which absorbed a considerable amount of the immigrants. But during the years 1926 - 1927 an economic crisis occurred in the country, from the toughest which the Jewish settlement had during the period of the British mandate, and in spite of the economic comeback between the years 1928 - 1929, the crisis was identified with all of the period of the Fourth immigration. In the period of the crisis about 23,000 immigrants decided to leave the country.
In the fourth Aliyah about 80,000 immigrants came to the Land of Israel, mainly from the countries of eastern Europe, half of the immigrants from Poland and the rest from USSR, Romania and Lithuania. In addition to that 12% of all immigrants were from Asia, mainly Yemen and Iraq. From the rest of Europe and America there were only a few immigrants. Due to the 10,000 immigrants who left the Land of Israel during those years, the contribution of the immigrants who stayed in the Jewish settlement in those years was very important and decisive.
Many of the new Jewish immigrants who arrived during this period, came as a result of increasing Anti-Semitism throughout Europe. The restrictive immigration quotas and laws of the United States kept Jews out. This group contained many middle class families that moved to the growing cities, establishing small businesses and light industry.