Judges 8:22
Then the men of Israel said unto Gideon, Rule thou over us, both thou, and thy son, and thy son’s son also: for thou hast delivered us from the hand of Midian. Then the men of Israel said unto Gideon, Rule thou over us, both thou, and thy son, and thy son’s son also: for thou hast delivered us from the hand of Midian.
After seven years of oppression by Midian, God raised up Gideon to deliver Israel. He was one of God's faithful and valiant rescuers, the instrument through whom that deliverance from Midian came. That raising up of a deliverer after seven years is the substance of the history, distinct from what the people afterward asked about hereditary rule.
Out of gratitude for the victory, the tribes of Israel credited Gideon himself with delivering them from the hand of Midian and offered him kingship, asking him to rule over them, both he and his son and his son's son after him. He refused the offer, answering that neither he nor his son should rule over them but the Lord should rule, and in that refusal he showed humility and acknowledged that the right to bestow such honor belongs to God.
The victory brought him great favor among the grateful people, with corresponding influence and responsibility. Instead of waiting for further direction from God, he yielded to dangerous temptation after success and used that influence to carry out his own plan for worship, which led Israel astray. After his death, when his authority was gone, the people returned to idolatry.