When St. Bathildes, wife of Clovis II, munificently refounded the abbey of Chelles, which St. Clotildis had instituted near the Marne, four leagues from Paris, she desired St. Thelchildes to furnish this new community with a small colony of the most experienced and virtuous nuns of Jouarre, who might direct the novices in the rule of monastic perfection. Bertille was sent at the head of this holy company, and was appointed the first abbess of Chelles, in 646, or thereabouts. The reputation of the sanctity and prudence of our saint, and the excellent discipline which she established in this house, drew several foreign princesses thither. Among others Bede mentions Hereswith, Queen of the East-Angles. She was daughter of Hereic, brother or brother-in-law to St. Edwin, King of Northumberland, and married the religious King Annas, with whose consent she renounced the world and, passing into France, in 646, became a nun at Chelles. Queen Bathildes, after the death of her husband in 655, was left regent of the kingdom during the minority of her son Clotaire III, but as soon as he was of age to govern, in 665, she retired hither, took the religious habit from the hands of St. Bertille, obeyed her as if she had been the last sister in the house, and passed to the glory of the angels in 680. In this numerous family of holy queens, princesses, and virgins, no contests arose but those of humility and charity. The holy abbess, who saw two great queens every day at her feet, seemed the most humble and the most fervent among her sisters, and showed by her conduct that no one commands well or with safety who has not first learned, and is not always reader, to obey well.

   St. Bertille governed this great monastery for the space of forty-six years with equal vigour and discretion. In her old age, far from abating her fervour, she strove daily to redouble it both in her penances and in her devotions. In these holy dispositions of fervour the saint closed her penitential life in 692.