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.
See also
Floridas | The Legend of King Arthur