The book of First Samuel is a part of the Old Testament in the Bible. It narrates the transition of Israel from a confederation of tribes to a unified monarchy. Key figures include the prophet Samuel, the first king Saul, and later, David, who would become a significant leader in Israel's history. First Samuel covers important events such as the anointing of Saul as king, his subsequent failures, and the rise of David. The book highlights themes of leadership, divine guidance, and the consequences of disobedience to God, setting the stage for the establishment of the Israelite monarchy.