The 'territory' of a Freeholding Lord is determined by a combination of what they have the power and/or influence to control and what the other members of the Accords are willing to recognize (the latter being significantly but possibly not solely influenced by the former). The former might be referred to as their 'effective' territory, while the latter could be called their 'official' territory.
A Freeholding Lord has all the authority, or at least most of it, of an Accorded supernatural nation within their territory. That is to say, they have treaty rights when dealing with members of other supernatural nations, and little else.
A Freeholding Lord is responsible for upholding the Accords among and with respect to his subjects.