In 601 the flames of war were rekindled by a rash move on the part of the exarch Callinicus. Agilulf again took up arms, seized Pavia and levelled it to the ground — a fate which the medieval chroniclers century by century record to have befallen the unhappy city. He made alliance with the heathen Avars, and with them ravaged Istria. He passed over northern Italy in a career of conquest: he carried the Lombard frontier forwards to include the valley of the Po. At Ravenna the imperial authority lingered on, and the exarch Callinicus was succeeded by Smaragdus, holding office for a second time. But the reality of power was passing, if it had not already passed, under the incessant energy of Gregory, into the hands of the pope, who had become the practical ruler of central Italy. It was in the year 603, when the Empire and the Lombards were at war, that Gregory shewed his aloofness from a strife which seems to have left the power of the Church undisturbed, by his rejoicing at the Catholic baptism of Adaloald, the firstborn son of Agilulf the Arian and Theodelinda the Catholic queen. Paul the Deacon indeed says, though he is unsupported by other witness, that Agilulf the father had already accepted the Catholic faith. As his sickness grew the great pope saw the future less dark than it had been during his life of anxiety. Rome, if impoverished and enfeebled, was securely in the possession of its bishop; and the conflicts which raged over northern and central Italy could hardly end, now that Catholicism was conquering the Lombards, otherwise than in favour of the papal power.
It may well be that this feeling coloured his attitude when news came to him of the revolution at Constantinople in 602. Maurice had long seemed to Gregory, as indeed he had seemed to his people, to be unworthy of the imperial throne. He was timid when he should have been bold, rash when prudence was essential to the safety of the State. His health had broken down, and fits of cowardice alternated with outbursts of frenzied rage. All the tales of him that reached Rome would increase Gregory's dislike and distrust. Already he had rebuked the Caesar to his face, and well he may have thought, when he heard of his deposition and murder by the centurion Phocas, that the warning he had given had been disregarded, and the judgment he had prophesied had come. With Maurice perished his whole family, with whom Gregory had been on terms of affectionate regard. Maurice had been an unwise, perhaps a tyrannical ruler, and certainly he had seemed to the pope an oppressor of the poor. And he had supported the patriarch in his overweening pretension to be "universal bishop." When Phocas therefore announced his accession, silent no doubt as to the butcheries which accompanied it, and dwelling rather on his orthodoxy and attachment to the Apostolic See, Gregory replied in language of surprising cordiality. The revolution was to him something that came from "the incomprehensible providence of God"; and he trusted that soon he should be comforted by the abundance of rejoicing that the sufferings
