Come, let us go to Gilgal and there renew the kingship

1 Samuel 11:1-15
When Saul heard their words, the Spirit of God came powerfully upon him, and he burned with anger. 
Then the terror of the Lord fell on the people, and they came out together as one. When Saul mustered them at Bezek, the men of Israel numbered three hundred thousand and those of Judah thirty thousand.
The next day Saul separated his men into three divisions; during the last watch of the night they broke into the camp of the Ammonites and slaughtered them until the heat of the day. Those who survived were scattered, so that no two of them were left together.
The people then said to Samuel, “Who was it that asked, ‘Shall Saul reign over us?’ 
But Saul said, “No one will be put to death today, for this day the Lord has rescued Israel."
Then Samuel said to the people, “Come, let us go to Gilgal and there renew the kingship.” So all the people went to Gilgal and made Saul king in the presence of the Lord. 
God moves Saul to make his appeal and the people to respond. For perhaps the first time since Joshua, the nation is united" a good beginning to the new king's reign.
Why?
The first victory seems led by Saul, but actually it the Lord with Saul and Israel, so they defeated Ammonites and slaughtered them.
After this battle, all tribes of Israel are united as one nation.
After this event, it is confirmed as the kingship of Israel and Saul. 
How?
Working with the Lord will come with joy and victory.  God is my only hope and salvation.