Saul, David, and Solomon. Their time of rule was known as The United Kingdom.
While Solomon started out well and earned great fame for his wisdom, in his later years he began to worship other gods and 1 Kings 11:4 says that "his heart was not true to the Lord his God, as was the heart of his father David."
The Bible blames Solomon's apostasy on the undue influence of his (count 'em) 700 wives and 300 concubines, but hey, he was a grownup and a king to boot. It's not always the woman's fault!
As a consequence, the rest of 1 Kings 11 tells how God split the Kingdom when Solomon's son, Rehoboam, took over.
From that time until the Babylonian Exile, the Bible speaks of the Divided Kingdom where what once was one nation of Israel becomes divided into the Kingdom of Israel in the north and the Kingdom of Judah in the south.
