Elated with their success, Civilis and Classicus doubted whether they should not give up the Colonia Agrippinensis to be plundered by their troops. Their natural ferocity and lust for spoil prompted them to destroy the city; but the necessities of war, and the advantage of a character for clemency to men founding a new empire, forbade them to do so. Civilis was also influenced by recollections of kindness received; for his son, who at the beginning of the war had been arrested in the Colony, had been kept in honourable custody. But the tribes beyond the Rhine disliked the place for its wealth and increasing power, and held that the only possible way of putting an end to war would be, either to make it an open city for all Germans, or to destroy it and so disperse the Ubii.