It's a pity this book isn't a standard text for secondary school students. The history of Islam is something all Westerners should learn in their teens - and don't. Robinson's book is both a revelation and an indictment of our collective ignorance.
"Islam, A Short History" is densely written, and sympathetically describes the evolution not only of the Islamic world, but also of the practices and tenets of this major monotheistic religion. Armstrong's tome not only dwells on the history of Islam, but also traces most major currents of thought within Dar al-Islam. She examines the evolution of Sharia (Islamic law), Sufism, the Ismailis, Twelver Shiism, and Wahhabism, just to mention a few of the streams that comprise this river. Best of all, this volume is written in plain English, simply written, incisive when need be, concise if not.
Ten maps show the ebb and flow of Islam: The illustrate the early conquests, the growth of the Umayyad Empire, the disintegration of the Abbasid Empire, the extent of the Seljuk Empire, the geography of the Middle Eastern Crusader states (in the 12th century), the threatening Mongol world in the 13th century, The Safavid Empire, the Moghul Empire in India, and the Ottoman Empire. The amirs, caliphs, ulamas, qadis (judges), and a host of other political, military, administrative, and religious figures are examined and put into their historical contexts.
"Islam, A Short History" contains a first-class 275-entry (!) chronology, a listing of 118 historical figures (!) from the history of Islam, a VERY exhaustive listing of additional readings (bibliography), and a good index. (The only weak point is a somewhat truncated glossary of Arabic terms.) Of the many books I have read about Islam, this is the one I would recommend as the first to read - it is a the perfect introduction to a fascinating (and almost unknown) new world.