Bertrand's fiery temper, however, and his love of fighting, were a continual source of trouble and anxiety to his parents. Before he was nine years of age he would often leave the castle without their knowledge, and collect all the children he met with on his way, and then fight them one by one, or try his strength against a number of them together. When he returned home, bleeding, and with torn and soiled garments, his mother would justly reprove him for behaving so little like a gentleman.
At last his fighting propensities increased to such a pitch that the country people complained of him to his father, and the Sire de la Motte was obliged to order a forfeit to be paid by the parents of all children who were found in his company. Nevertheless Bertrand still contrived to get out of the castle secretly, and to lead the little villagers to their mimic battles. His father, as a last resource, shut him up in the dungeon of the castle, and in this dreary place he remained four months. But one evening a maid-servant, whose office it was to bring him his food twice a day, left the door open behind her, and Bertrand managed to slip out, not forgetting in his haste to turn the key upon her, in case she should betray him to his parents. Then he ran as fast as ever he could to a field, unfastened a mare from one of his father's ploughs, mounted it, laughing heartily the while at the ploughman, who was rushing after him, and galloped as far as Rennes, without saddle or bridle, to the house of his aunt, a sister of the Sire de la Motte, who was married to a knight of great honour.
His aunt had often heard of his misconduct at home, and was not at all pleased to see him arrive in such plight. She began scolding him in harsh words, when luckily for him his uncle intervened in his favour, reminding his wife that Bertrand was only a child, and had done nothing yet to forfeit his honour. "He is brave and spirited," said the good knight; "let us keep him in our house, and see if we cannot transform him into a great captain for the glory of Bretagne."
Bertrand remained with his uncle at Rennes until he was sixteen, and learned from him all the accomplishments necessary for a knight. Moreover, he learned to be gentle and courteous to those around him, and in these happier circumstances the good points of his character shone forth, and his violent temper was curbed, whilst his spirit remained free. It is related of him that he was so generous, that when he met with any poor persons, and had no money with him, he would give them some of the very clothes he wore, and if he had only a penny would share it with those who were in need. He found his greatest delight in listening to his uncle's stories of battles and sieges, and when some noble exploit was related, would clap his hands for joy, whilst his eyes shone like fire.