As was the custom in the Grail Family, Herselojde was sent away from Munsalvæsche, the Grail Castle, to become the wife of a noble lord; in her case, this lord was Castis, the King of Wales and North Wales. Their marriage was unconsummated due to Castis’ untimely death, and Herselojde, as a maiden, inherited Castis' kingdom.
She threw a tournament at her city of Kanvoleis, promising herself and her lands to the knight who won the tournament. The noble Gahmuret was the victor, and thus found himself bound to marry Herselojde, even though it was not his wish. After their marriage, Gahmuret secured permission from Herselojde to seek adventure, and was killed fighting in the Middle East.
Herselojde went slightly mad and soon gave birth to Perceval (Percivale), who she saw as the reincarnation of her husband. She raised him in seclusion, ignorant of knighthood and chivalry, in order to protect him from the same fate that befell his father. While she was living in this sequestration, King Lähelin entered and conquered her lands. Perceval eventually found out about knighthood from some passing knights, and insisted on going to the court of King Arthur. When he left, Herselojde died from a broken heart.
The summary of her guidelines to Percivale was as follows:
Where ever you see a church go in there and say your paternoster. And if you see food and drink and no one shows enough courtesy to invite you, grab some. And if you hear a scream, ride towards it, especially if it is a woman's yell. If you see a beautiful gem take it and give it someone else, and you will be praised. If you see a lovely woman, love her then, either she wants it or not, in that way you will be a better and more appreciated man than before.
Herzeleide is German for 'heart sorrow', and Wolfram probably created the name to express the queen’s sorrow for losing her husband. Her character is unnamed in Chrétien de Troyes’s Perceval.