What was the Kingdom of Judah and why was it important?

The Kingdom of Judah was the small inland enclave centred on Jerusalem, in Palestine and to the west of the Dead Sea. It appears to have been founded around the beginning of the tenth century BCE or perhaps a little earlier. It was nearly always under the shadow of its more powerful neighbours and its capital was finally destroyed in 586 BCE, with many of the inhabitants deported to captivity. However, even before 586, the kingdom had already been reduced to just the city of Jerusalem and its immediate environment. However, the Jews returned around 500 BCE and redeveloped their land.

Judah was important because Judaism developed there and became one of the most enduring world religions, as well as being the parent religion of Christianity and Islam.