The book "Code for the Management of Armies on the Field of Battle, Approved by the Laws and Customs of War on Land", written by Francis Lieber and the United States Army Corps, is one of the most important documents that govern the conduct of armies in times of war. This book examines in detail the principles of humane treatment of prisoners of war, civilians and property during armed conflicts on land. This code defines the standards of military law that all parties to a conflict must adhere to in order to reduce human suffering and property damage. Thanks to this book, the standards of humane treatment of troops become universally accepted and mandatory for implementation during war on land.