In two volumes, the book «Islamic Countries» on Islamic Countries represents a valuable reference for researchers in historical sciences. It was written by Shams al-Din al-Dhahabi, a hadith scholar and a memorizer. He combined two features that were only combined by a few unique individuals in our history. In addition to his extensive knowledge of Islamic history, events and men, he combined extensive knowledge of the rules of criticism and modification of men, so he was a school in itself.