in Architecture, History | June 11th, 2026 Leave a Comment

Ask around for what every­one knows about Istan­bul (oth­er than that it used to be called Con­stan­tino­ple), and you’ll find that the pres­ence of Hagia Sophia there comes right to many a mind. Less like­ly to be men­tioned is its prone­ness to earth­quakes, though it tends to rank just below Tokyo on lists of cities under the great­est threat from fault lines below. These two char­ac­ter­is­tics turn out to have a con­nec­tion, man­i­fest in the ongo­ing seis­mic retro­fitting of Istan­bul’s sym­bol­ic cathe­dral-turned-mosque-turned-muse­um turned-mosque-again. Hagia Sophia is one of the most cel­e­brat­ed reli­gious build­ings stand­ing; keep­ing it that way requires a seri­ous engi­neer­ing effort, as explained in the new B1M video above.

Since it was first built in the fourth cen­tu­ry, Hagia Sophia has actu­al­ly sus­tained severe earth­quake dam­age quite a few times, includ­ing a com­plete col­lapse of its cupo­la in the year 558 and par­tial col­laps­es in the tenth and four­teenth cen­turies. The con­struc­tion of its famous cen­tral dome, along with the small­er sub-domes that sup­port it, gets a sec­tion of its own in the video.