Jewish history goes back two thousand years or far longer, depending on ones' point of view. this difference of opinion revolves around a major historical event the destruction of the second temple of Jerusalem by the Romans in 70 Ce, which brought about the end of the temple based ceremonial religion of that region and the widespread dispersion of it people to lands far away from Israel.
When we study the Judaism practiced today, what we are really studying are the forms of Jewish belief and religious practice that largely came into existence after the destruction of the Second Temple.
Jewish man with Menorah
Source: World Religions Text Book: Section Judaism