The Book of Joshua begins after Moses' death, when Joshua takes over the mantle of leadership. God promises Joshua that He will be with him in conquering the Canaanite armies, and the Jews swear to follow Joshua's command. Joshua then sends two spies into the city of Jericho to find out what the attitude of the Canaanites is towards the Jews. The spies enter the house of a woman named Rahab, whose home is in the city wall. Rahab tells them that word of the Israelite victories have scared the Canaanites, and that they are wary of the Jews. In return for this information, she asks that she and her family be spared when the Jews capture the city of Jericho. The spies escape through her window and pass on Rahab's message to Joshua.
The Jews then cross the Jordan River. The priests carrying the Ark go first, and the Ark causes the water to split almost like the waters of the Red Sea split so that the Jews pass through on dry land. The Jews travel to Jericho and prepare to do battle. Rather than scaling the walls, however, they follow God's command and simply circle the city's walls seven times, blowing horns during each cycle. The walls fall down, and the Jews attack the city, leaving Rahab's family unscathed. God's command was that no one should take from the spoils of Jericho, but one man named Achan does not listen. In response, God causes the army to fail in their next battle with the city Ai. The Jews realize this and punish Achan for his sin, after which they are successful in overpowering the people of Ai.
In the wake of these battles, the Gibeonites come to the Jews to make a treaty with them. The Gibeonites are actually a tribe of Canaanites, but Joshua does not know this. Therefore, he erroneously makes a treaty with them, although he has sworn to do battle with all who dwell in Canaan. When other Canaanite nations attack the Gibeonites, Joshua fights in their defense. In order to assure visibility during the battle, Joshua asks God to make the sun stand still in the sky rather than setting, an unprecedented request. God listens, and the Jews win the battle.
At this point, the Book of Joshua discusses the many military campaigns of the Jews as they take over the Land of Israel. It then goes on to list the sections that the land was divided into, with each of the twelve tribes inheriting a different section. At the conclusion of the book, Joshua addresses the people before his death, encouraging them to follow God's word always. The book ends with Joshua's death and burial, as well as the burial of Joseph's bones.