Since Justinian’s rule (527–565), the Roman Empire’s political situation had deteriorated rapidly. The Persians, the empire’s archenemies, had completely overwhelmed the eastern regions with constant war. Earlier peace talks had failed, and in the summer of 626, a Persian force stood armed and ready just across the Bosporus. The only thing separating this army from Constantinople was a narrow strait. While facing this imminent attack across the strait, the city also faced the threat of Avar and Slavic invasions from both land and sea. The invaders pillaged the surrounding towns and villages, effectively cutting the capital off from supplies, and began setting up heavy war equipment in the process. Their leader, the Chagan, was a shrewd man who had nearly captured the emperor a few years earlier. The threat was even more dire this time because the emperor had left the capital on a campaign against the Persians two years earlier and was much too far away to intervene in time. Instead, the heavy mantle of responsibility lay upon two men, the Patriarch Sergios and the Roman general Bonos, both of whom sought to prevent a mass panic and scrambled to quickly organize the city’s defense.

The Patriarch’s encouragement provided the necessary will to persevere and solidarity within the population. General Bonos also proved his ability to lead by organizing an effective defense of the city walls and by motivating his men. They fought daily small skirmishes against the Avars and the Slavs in front of the city gates. The decisive turn in the siege, however, was achieved with trickery. With a cunning bluff, Bonos was able to keep the Persians from attacking, which in turn allowed him to thwart the Avar attack. Bonos learned that the Slavs planned to attack the city from water upon receiving a fire signal, which would distract the defenders of the city so that the Avars could storm the walls unhindered. Instead, Bonos cleverly gave the supposed attack signal himself, which led the Slavs to attack, where they were surprised and crushed by the waiting defense forces. The blind-sided Avars could only helplessly watch the bloodbath of their allies and were forced to break off their siege. They would to never fully recover from the decisive defeat. The citizens of Constantinople, on the other hand, were the triumphant victors, and subsequent sieges by Arabs, Bulgarians, and Magyars seen as harmless in comparison. It was not until the 13th century that crusaders were able to conquer the city. But by then, the Constantinople of the seventh century had long since disappeared.