From after the conquest of the land under Joshua until the formation of the first Kingdom of Israel, the Tribe of Reuben was a part of a loose confederation of Israelite tribes. No central government existed, and in times of crisis the people were led by ad hoc leaders known as Judges (see the Book of Judges). In this period, according to the ancient Song of Deborah, Reuben declined to take part in the war against Sisera, the people instead idly resting among their flocks as if it were a time of peace, though the decision to do so was taken with a heavy heart.