[James Howard-Johnston] is admirably clear in describing his approach
Chase Robinson, Times Literary Supplement
the book abounds with interesting arguments ... Howard'Johnston's critical eye and clarity of exposition are sustained from start to finish ... this volume is a rich and remarkable achievement: it constitutes a truly foundational work for the study of the 'new world order' of the seventh-century East.
Brian Croke, English Historical Review
Witnesses to a World Crisis will appeal to layman and scholar alike thanks to the balance being struck between critical analysis en detail and the bigger picture of international relations between byzantines, Persians and Muslim Arabs, presented in lucid prose. The reader is never in danger of getting lost on this tour de force, since the analysis of the sources proceeds along chronological lines, which allows Howard-Johnston to weave together the strands of evidence as he goes along, and to lead the reader to an understanding of how developments in this period shaped the following centuries, reaching as far as the present day.
Berenike Walburg, The Medieval Journal
a pandramatic narrative, limpid and exhilarating in equal measure, as gripping as its emphases are well-judged, with not a word wasted.
Professor Aziz Al-Azmeh, Central European University
Few events have been more decisive for the history of the world than the preaching of Muhammad and the subsequent expansion of his followers. After this book they will never seem the same again.
John Moorhead, Australia Journal of Politics and History