The ban was a political and territorial institution in the Frankish kingdoms, meaning a grant of power to command men. Following its civil, military or religious meanings, it ended up as a metonym for territory where such a grant applied. When the public rights of assembly members came to be held by a family line, the ban was confused more or less (sometimes totally) with seigneurial power in the Middle Ages.
It related to the recognition of the rights of Christian communities organised by a specific political assembly, representative of free men adhering to this group. The king, anxious for the good evangelisation that the bishop and troops of monks guaranteed to him, participated in its foundation and granted it a generous financial and territorial basis from the fisc (i.e. from the vast royal lands). The territorial granted to the grand ban appeared in the 7th century at the borders of Austrasia and rapidly developed at the end of the Merovingian era.
Major aristocrats, whether in their duties as counts or dukes, or at the bans' initiative via their clientele networks, supervised or oversaw these semi-autonomous entities, highly reinforcing their spiritual and temporal power. A secular economic life developed around the monasteries, and their founders' families were also buried there, with both developments turning them into sacred sites, perpetuating the hierarchy of the episcopal city and the harmony of the dioceses from the Late Roman Empire. Troubles and rivalries between these new semi-autonomous princes and their bands of troops, along with the development of fiefdoms brought about a collapse of the Late Roman structures and of those of the first kingdom of the Franks.