His heir, because Absalom has murdered his older brother Amnon out of revenge (2 Samuel 13).
Absalom after years in exile has mustered a large rebel army to overthrow David as king. Even though David had ordered mercy for his son, Absalom is killed.
As we read this terrible, tragic story of a suffering country and suffering family, we should remember how Samuel had responded initially to Israel's desire for a king (1 Samuel 8).
The compilers of our Bible wanted us to reflect on the truth of Samuel's prophecy.
And, we can read in this terrible tragic tale a reminder of the pain in families as well as in nations.