While technically a "Dictionary of Countries," it is often referred to in the same context as an encyclopedic geographical work.

This is the most famous of the three, focusing on the early Islamic conquests. English Title: The Origins of the Islamic State PDF Access:

Detailed descriptions of Iran, the Arabian Peninsula, Iraq, and Syria, interspersed with poetry and religious traditions.

The Kitab al-Buldan (The Book of Countries) stands as one of the most influential masterpieces of medieval Islamic geography. Written during the golden age of the Abbasid Caliphate, this foundational text shaped how scholars understood the geopolitics, trade routes, and cultures of the known world.

Al-Ya'qubi was an administrative official and historian who traveled extensively throughout the Islamic world. His Kitab al-Buldan is particularly famous for its systematic, bureaucratic approach.

Understanding Kitab al-Buldan : The Ultimate Guide to Classical Islamic Geographies