i Register
In some senses, castellan is marked as obsolete, historical. Watch for register when choosing this word.
noun
A feudal lord with a fortified manor.
The governor or caretaker entrusted to oversee a castle or keep for its lord.
The inferior secular senators are ninety-two, containing the ten crown-officers, and eighty-two castellans. The latter are again divided into thirty-three great castellans, and forty-nine little castellans.
Castellans, often exercising control over a few villages and half a dozen small lordships, transformed their banal lordships into quasi-sovereign mini-states, independent of royal or comital sanction or control.