Without its senior service, the Third Imperium would not exist. The navy is entwined in the politics and economics of the Imperium, a training ground for the great nobility, and a route to social advancement for the general populace. The Imperial Navy details this massive force, from the great fleets down to a band of new recruits. How are the sector and subsector fleets organised, commanded, and provided with warships? How would the Imperium fight – and win – an interstellar war? How is a starship crew organised? What is the underlying design philosophy of Imperial warships? How do major ships and their escorts interact? How would the Old Expanses fleet respond to renewed conflict with the Solomani Confederation? The Imperial Navy has the answers.