Book excerpt: This book examines the Avar siege of Constantinople in 626, one of the most significant events of the seventh century, and the impact and repercussions this had on the political, military, economic and religious structures of the Byzantine Empire. The siege put an end to the power politics and hegemony of the Avars in South East Europe and was the first attempt to destroy Constantinople, the capital of the Eastern Roman Empire. Besides the far-reaching military factors, the siege had deeper ideological effects on the mentality of the inhabitants of the Empire, and it helped establish Constantinople as the spiritual centre of eastern Christianity protected by God and his Mother. Martin Hurbanič discusses, from a chronological and thematic perspective, the process through which the historical siege was transformed into a timeless myth, and examines the various aspects which make the event a unique historical moment in the history of mankind – a moment in which the modern story overlaps with the legend with far-reaching effects, not only in the Byzantine Empire but also in other European countries.