By Kyle Orton (@KyleWOrton) on March 20, 2016

Tom Holland’s In the Shadow of the Sword: The Battle for Global Empire and the End of the Ancient World (2012) is a smooth read, a feat hardly foreordained in a book that exceeds 500 pages in length. Holland writes narratively, giving his interpretation of the most likely scenario—and then presents the evidence in full in endnotes for those who wish to test his thesis. This has gotten him into trouble among haughtier reviewers for writing “pop history”, which appears to mean an exploration of the past that there is a danger people will want to read.

What Holland sets out to do is trace the period of Late Antiquity leading up to the great war between the Roman and Persian Empires at the dawn of the seventh century, and the emergence from their mutual ruin of a new power: Islam. Often when the story of Islam’s origins is told, even in works that take quite a critical view of the Muslim Tradition, an overwhelming sense is retained of tabula rasa: that (1) Islam appears from nowhere among the Arabs, as if delivered from the sky, and then (2) the Arab armies carry the new faith across the Near East and North Africa, marking a clean break with the past. Holland’s central argument is that these two premises are mistaken, that the elements that go into Islam’s make-up are distinctly recognisable from the place and time it originates, albeit that place and time are not quite where the Tradition locates them.

These conclusions of Holland’s have caused the controversy around the book, but one of the things a reader takes away from the book is a sense that the controversy is itself odd: without the Tradition—which dates to about two centuries after the events it describes—there would not actually be much of a mystery about where Islam came from and when (at least in broad outline), and on no other subject is it considered incumbent on historians to keep their conclusions within the framework of the claims made by a religious tradition.