The book "History of the Inquisition of the Middle Ages; Volume III" by Henry Charles Lea is the third volume of a historical study devoted to the activity of the Inquisition in the Middle Ages. The book examines the events of the Inquisition, its role in the church and political life of that time, methods of investigation and punishment of "heretics". The author provides a detailed analysis of historical documents and eyewitness accounts, making this book a valuable source for the study of the Inquisition. "History of the Inquisition of the Middle Ages; Volume III" offers the reader a deep dive into the complex and not always pleasant history of this institution, which left its mark in the national and religious conflicts of Europe.