The aged Aymon had already fallen into the hands of the emperor's adviser, Turpin, who solemnly promised that no harm should befall him.

But in spite of this oath, and of the remonstrances of all his peers, Charlemagne prepared to have Aymon publicly hanged, and consented to release him only upon condition that Aymon would promise to deliver his sons into the emperor's hands, were it ever in his power to do so.
The four young men, knowing their father safe, and unwilling to expose their mother to the unpleasant experiences of the siege which would have followed had they remained at Pierlepont, now journeyed southward, and entered the service of Saforet, King of the Moors.

With him they won many victories; but, seeing at the end of three years that this monarch had no intention of giving them the promised reward, they slew him, and offered their swords to Iwo, Prince of Tarasconia.
[Sidenote: Fortress of Montauban.] Afraid of these warriors, yet wishing to bind them to him by indissoluble ties, Iwo gave Renaud his daughter Clarissa in marriage, and helped him build an impregnable fortress at Montauban.

This stronghold was scarcely finished when Charlemagne came up with a great army to besiege it; but at the end of a year of fruitless attempts, the emperor reluctantly withdrew, leaving Montauban still in the hands of his enemies.
Seven years had now elapsed since the four young men had seen their mother; and, anxious to embrace her once more, they went in pilgrims' robes to the castle of Pierlepont.

Here the chamberlain recognized them and betrayed their presence to Aymon, who, compelled by his oath, prepared to bind his four sons fast and take them captive to his sovereign.