During his time ‘on the run’ from Saul’s pursuing troops, David had built up strong support among the southern clans and cities in Judah.
When Saul and his sons died in the battle and northern tribes struggled to find a successor to Saul, the southern tribes made David King in the south at Hebron where he ruled for Seven and a half years.
Amidst much plotting and skullduggery, the last son of Saul is killed, and the northern tribes then sent representatives to Hebron to ask David to be King over both North and South. He accepted and ruled as King for thirty five years over all Israel and Judah.
My uncle Zokar reigned for Eight years and died without an heir and my grandmother from Medes who was the only royal member left and kingmaker was summoned to give the people of Persia a solution.