Mares li Sires de Roestoc, Marke the Lorde of Roestok
One of the knights (mentioned in the Vulgate as a king) who swears to go for a year and a day in quest of Lancelot. He is perhaps identical with Marés.
Mares, Damsel des
Five days after the visit of Ban and Merlin, a rich knight of the neighborhood asked for the Damsel's hand in marriage. She meekly but firmly refused, confessing at last that she was with child by King Ban. Sir Agravadain requested the young lover, whose name seems to have been Leriador, to wait for two years and then try again. Instead, Leriador besieged the castle and Agravadain had to beat him off.
The Damsel seems to have remained unmarried after giving birth to her son, Sir Ector de Maris, who resembled his father, King Ban.
After Sir Agravadain's death, the castle was held by his son, Ector's uncle and the Damsel's brother. The Damsel seems never to have forgot her lover, for she always kept a sapphire ring he had given her. This ring had been given him by his wife, Elaine of Benwick, who kept another one like it. Years afterwards, the Damsel des Mares was able to prove to Lancelot that her son was his half-brother by means of this ring.
The damsel left her family's castle at least once, to travel to the Royal Minster in Gaul and meet Lancelot's mother, Queen Elaine.
Mares, le Seignor
Des Mares, Marasse
The castle Des Mares would probably be near the sea (mare).
Kings Ban and Bors stopped here during their visit to Arthur in Britain. The castellan, Agravadain des Vaus (not to be confused with Gawaine's brother, Agravaine), had a beautiful daughter whom Merlin admired and caused to sleep with Ban, resulting in the birth of Lancelot's half-brother, Ector de Maris.