The High Overseer is a book found in Dishonored.
[Excerpt from a series on Overseer roles and rituals]
Over the centuries, the Abbey of the Everyman has held its place as the dominant religion across the Isles. Not only do its adherents call it the only meaningful faith, but aside from a few tolerated variants, they castigate the followers of other religions as heretics, actively resulting in harm rather than harmony.
A key component to the Abbey’s health is the High Overseer, venerated by all other Overseers, the women in the Orocular Order, and the congregations from each town and city across the Empire. The High Overseer is called upon to interpret the Seven Strictures and to initiate important ceremonies such as the Fugue Feast and the end of each Calendar year.
Above all, the High Overseer must embody the Strictures, serving as a living example of their perfection.
Upon the death of the acting High Overseer, it falls upon a council made up of elder Overseers to call for the Feast of Painted Kettles, the first step in the arduous process of choosing a new leader for the Abbey.