What is his story? What became of him?
You can read about him in the Bible: 2 Samuel, 1 Kings, and 1 & 2 Chronicles.
I am almost certain that he isn’t recognized as a saint though. I think it was because he went a bit ‘New Age’ in the last part of his life. That’s not to say that he didn’t find salvation, especially considering his fame in Israel and building the first temple. His father King David is recognized as a saint though - St David.