The Book of Judges tells of events that occurred after the Israelites settled in the Promised Land. The events in this book happened over a period of about 150 years.
This book describes how the Israelites repeatedly sinned against Yahweh during this time. They worshiped false gods and did the same wicked things as the peoples who lived around them. Therefore, God would allow enemies to defeat and oppress the Israelites. Eventually, the Israelites would call to Yahweh for help. Yahweh would then cause someone to help the Israelites defeat their enemies. This person was called a "judge." The Israelites would live in peace until the judge died.
This book traditionally has the title "Judges" because it gives accounts of some of the main leaders or judges in Israel before there were any kings over the people. Unless there are good reasons for following the title in other Bible versions, the translator should probably use the title "Judges" or a title such as "The Book about the Leaders in Israel."
These were men and women whom God chose to help the Israelites defeat their enemies. After defeating their enemies, these leaders usually continued to help the people by deciding disputes among them. They also helped them make important decisions. Many of these leaders served all the people of Israel, but some of these leaders may have served only certain tribes.
During this time, the twelve tribes of Israel were independent of one another. They were not a unified nation with one ruler. The tribes would sometimes help each other when enemies were threatening them.