What is a relationship between Judaism and Judah?

when the nation of israel split in a civil war, there were two kingdoms -- the kingdom of israel (10 tribes) and the kingdom of judah (2 tribes, the larger being judah). The 10 tribes were exiled and lost and the jews who are alive descended from the kingdom of judah, thus they are known as the judah-ites (yehudim in hebrew) and the english word "Jew" and "judaism" are developed from this. nothing to do with an apostle.