Groups claiming affiliation with Israelites are groups which trace their descent from the ancient Israelites. The most significant events which propelled large numbers of Jewish and pre-Judaic Israelite communities out of the Land of Israel were the fall of the northern Kingdom of Israel in about the 720s BCE to the Assyrian Empire and the southern Kingdom of Judah in 586 BCE to the Babylonian Empire, but there have been other events and periods when Israelites left the Land, either as individuals or in groups. These diaspora communities came into existence as a result of Jews and Israelites fleeing the land before the onslaught of invading forces, because of forced deportations, or enslavement, and sometimes voluntarily. Some families or whole communities have had to move from one country to another because of persecutions, and some just ceased to exist. Although some form of contact had been maintained between most of the main Jewish communities in the diaspora over the millennia, contact had been lost with some communities, which came to be regarded by the mainstream communities as lost.
As a result of the isolation of some communities, the practices and observances have diverged in some respects. Several groups of people from diverse parts of the world have claimed an affiliation with or descent from the ancient Israelites. Some claim such affiliation on the basis of affinity to the Jewish people, while other groups claim such affiliation independently of such affinity.
Since the establishment of the State of Israel, affiliation to the Israelites is raised in the form of "who is a Jew?", which arises in the context of an individual's or group's request to immigrate to Israel under that country's Law of Return.
It is accepted that the Jews and the Samaritans are descendants of the ancient Israelites.
Jews came to Kerala and settled there as early as 700 BCE in order to trade. Cochin Jews, also called Malabar Jews, are the descendants of ancient Jews who settled in the South Indian port city of Cochin. They traditionally spoke Judæo-Malayalam, a form of the Malayalam tongue, native to the state of Kerala, in India. Several rounds of immigration of the Jewish diaspora into Kerala, led to a diversity among the Cochin Jews.