Political mutilation in Byzantine culture

[1] By blinding a rival, one would not only restrict his mobility but also make it almost impossible for him to lead an army into battle, then an important part of taking control of the empire.

The mutilation of political rivals by the emperor was deemed an effective way of side-lining from the line of succession a person who was seen as a threat.

Castrated men were not seen as a threat, as no matter how much power they gained they could never take the throne, and numerous eunuchs were entrusted with high and confidential offices in the Byzantine court and administration.

Since God was perfect, the emperor also had to be unblemished; any mutilation, especially facial wounds, would disqualify an individual from taking the throne.

[4] Blinding as a punishment for political rivals and a recognized penalty for treachery was established in 705, although Phocas (r. 602–610) used it earlier during his rule as well, becoming common practice from Heraclius (r. 610–641) onwards.