Although its exact extent is unknown and its boundaries do not coincide with the later Breton March; it included the Rennais and Nantais territories (French: pays), and parts of the Vannetais and Maine.
Kuigi selle täpne ulatus on teadmata ja selle piirid ei langenud kokku hilisema Bretooni margiga, sisaldas see Rennes'i ja Nantes'i territooriume (prantsuse pays) ning Vannes'i ja Maine'i osi.