Earthquakes and Istanbul: How did Hagia Sophia’s dome collapse in 558?

Istanbul in the sixth century A.D. was much different than it is today. The metropolis was under Byzantine rule, its name was known as Constantinople, however one thing was the same: It was situated on an active seismic zone, and the frequency of earthquakes was much worse in fact.

During the reign of Emperor Justinian I (527 A.D.-565 A.D.), the tremors had become an almost constant presence. While a powerful earthquake in 533 A.D. rattled the city, citizens found refuge in the Forum of Constantine and escaped unharmed. This close call, however, proved to be a mere tremor before the storm. Historical records detail a series of smaller quakes that rattled Constantinople throughout the 540s A.D. and into the mid-550s.The year 542 A.D. was marked by a devastating plague epidemic, further impacting the population. Despite these challenges, people continued to live their lives, unaware of what to expect.

Two precursor earthquakes struck on April 16 and Oct. 19, 557 A.D., followed by the third and most significant earthquake in December.

According to Agathias, Constantinople was “almost completely destroyed” by the earthquake. Noting that it was a unique earthquake in terms of its duration and intensity, Agathias explained that the city had been affected by a severe winter before the earthquake.

According to Agathias, the great earthquake began around midnight, when most people were asleep, and successive tremors accompanied by “screams and voices” likened to thunder by the terrified populace. Panicked citizens began to evacuate their homes and gather in the streets and alleyways. Agathias noted that there were very few “wide open spaces completely unobstructed” in the city. However, he also reported that the sleet affected those who stayed outside and that everyone “suffered greatly from the cold.” Agathias also reported that most people took shelter in the city’s churches and that the Rhegium area, close to the city’s harbor, suffered the greatest structural losses.

At dawn, as the earthquakes subsided, people rejoiced and began searching for their loved ones. By daybreak, the extent of the devastation became apparent in the city, with severe damage to the dome of Hagia Sophia.

Today in history, Hagia Sophia dome collapsed

On May 7, 558 A.D., the city experienced another devastating earthquake that caused even more destruction. The dome of Hagia Sophia completely collapsed during this event. Historian Procopius, who lived at the time, said, “All the buildings around Lake Kucukcekmece were destroyed down to their foundations.”

The clearest archaeological evidence of the devastating earthquake in 558 A.D. can be found in the sixth-century buildings discovered in the ancient city of Bathonea, situated in the basin of Kucukcekmece Lake. One poignant discovery was the finding of two individuals huddled together under a collapsed dome within one of these structures. A coin from that era, found near the couple, serves as a key piece of data, providing insight into the timing of this tragic event.

After each of these fatal earthquakes, which caused a brief population shift, Emperor Justinian I instituted a short period of mourning. He did not wear his crown for 40 days following the earthquake. On each anniversary, the earthquake was commemorated in the annual liturgy of supplication.

According to Agathias, following the earthquake, there was a temporary increase in charitable acts and favors among the wealthy. However, as time passed and memories of the earthquake faded, people reverted to their previous attitudes and behaviors.