The Jews got their name from Judah the fourth Son of Israel (Jacob) that was the predominant and the identifiable populace at that time of Jesus in His-story. The other tribes had merged with the gentiles worldwide and lost their identity. Only a few (especially the believing line) could trace their genealogy and that is how we have the genealogy of the Man Jesus even from Adam. The search for the other tribes of Israel are still on. India has many Jewish descendants!

The united kingdom of Israel broke up into Israel and Judah. The people of Judah scattered world-over as modern-day Jews after the Babylonians captured them in 586 BC. Earlier, the people of the northern kingdom that retained the original name Israel were taken captives by the Assyrians and got scattered in 722 BC. They lost their identity soon as they mingled with the rest of the world population and accepted their gods. A large chunk of these moved to the Indus valley and India in search of their Thamizh Ancestors. They gave rise to many towns on the way that are named in Thamizh. For eg. Kandhahar is from the Kandhan and River Murugab is from the Murugan of the Thamizhar.