David seemed to pick up strength as he went along in life. Solomon was the other way. Solomon started out strong, but he tailed off at the end—as his weakness, probably with age, began to become apparent.
What Solomon did set the die for most of the rest of Israel and Judah's kings. So when Solomon died, his son, Rehoboam, came to the throne and followed right in the path of his father, Solomon. So a rebellion broke out—the result of which was the separation of Israel and Judah into two nations. The ten-tribe Israel was in the north, and the two-tribe Judah was to the south.