Over the main entrance door of the great church of Hagia Sophia in Istanbul, there’s a mosaic that shows Christ enthroned with an unknown Byzantine emperor kneeling down at Christ’s feet. He thus shows his humility before god, but of course expresses this humility in a most arrogant gesture. It’s so high up on the wall that many people miss it as they are at that moment distracted by the now visible and spectacular interior of the church. It’s probably about 1000 years old, yet it still glows with golden light, one of the rare documents indicating how the Byzantine emperors articulated their divine rule with art.