Thou shalt not make unto thee any graven images, or any likeness of any thing that is in heaven above ...
Exodus 20:4

eikōn = likeness   +
klan = to break
... giving us, from the Greek, the word iconoclast. And the iconoclasts were out in force during the 8th century, trying to rid churches of all heavenly images.

We'll never know how many priceless works of art were destroyed during that time. We're lucky to have what remains. This work was created much later, in the 13th century, a century of two before the Hagia Sofia was converted to a mosque.

Again, lucky for us, these mosaics were merely plastered over at that time and not destroyed.