3. And, lastly, the power of the papacy was at once evidenced and increased by the revival of its missionary energy. What Pelagius II. had stayed, Gregory the Great accomplished--conversion of England by the mission of Augustine. Spain, too, was won from Arianism by a personal friend of Gregory's, though without Roman intervention;[3] and within Italy itself the {63} pope began the great work of the conversion of the Lombards to the Catholic faith, with the full teaching both of the Tome of Leo and of the Fifth General Council. Gregory sent the Acts of the Council to be taught to the little child Adalwald, the Lombard king. Thus in each of these three directions the progress of papal power is connected with the influence of Gregory the Great. It is of his papacy therefore that we must speak as the critical point in the upward movement. Between 574 and 590 Gregory gained experience in many ways. To a strict monastic training he added, in 579, the employment of papal apocrisiarius (or envoy) at the imperial court at Constantinople. Here he became intimate with the chief ecclesiastics, with Anastasius, who had been deposed from the patriarchal see of Antioch, and who came to regard him as "the very mouth and lantern of the Lord," with Leander of Seville, who had come to lay the needs of the Catholic cause in Spain before the emperors,[4] and with the imperial family. [Sidenote: Gregory as abbat.] About 586 he returned to Rome, and became abbat of the monastery in which he had formerly served. It was there that he completed his commentary, or _moralia_, on the book of Job, which he had delivered as lectures at Constantinople, an epitome of Christian theology and morals. It was then that he saw the bright lads from Deira, who first turned his thoughts to the conversion of England.[5] The controversy of the Three Chapters was still lingering on in Italy, and it was Gregory who was given the task of inducing the Istrian {64} bishops to accept the decisions of the Fifth General Council. [Sidenote: Gregory elected Pope, 590.] So skilful did he prove himself as a controversialist, as an administrator, and as an adviser of Pelagius, that he was elected with enthusiasm to succeed that pope in 590. [Sidenote: The pastoral rule.]