histology is what you call the history of writing about history
The Iconoclast controversy caused the banning of religious icons in Christianity and the killing of supporters of the veneration of icons. The iconoclast controversy happened twice during the Byzantine Empire. This impacted the growing divergence between Western and Eastern Christian traditions, but the Western Church stood firmly with the belief that icons could be used, but the Church was still unified at the time.
It's called Nullification
