The lord of Lestroite Marche held it against the King of Norgales, the Duke of Cambeninc, and the King of the Hundred Knights with the latter's seneschal Marganor, putting the castle somewhere in the marches between Norgales and Cambenet; indeed, its name means "the narrow march".

The lord of Lestroite Marche had one child, a daughter, who for some reason could not hold the castle after him. To help defend the castle and try to find his daughter a good husband at the same time, this lord established the custom that any knight who accepted his hospitality must spend half a day defending the castle. Ector de Maris, at that time a Queen's Knight, vanquished Marganor and restored peace to the area, although he cried off from marrying the damsel by pleading that he already had a lady.