The Book of Joshua describes the Israelites conquering Canaan under Joshua's leadership after Moses' death. Key events include crossing the Jordan River, marching around Jericho which causes its walls to fall, defeating the Amorite kings who attacked Gibeon, and dividing the land among the tribes. The book emphasizes obeying God and avoiding assimilation into Canaanite culture. Joshua prepares the people to continue without him before he dies at age 110.