Oswiu's assent to the vigorous measures of organization undertaken by a Greek monk, Theodore of Tarsus, whom Rome despatched in 668 to secure England to her sway as Archbishop of Canterbury, marked a yet more decisive step in the new policy. The work of Theodore lay mainly in the organization of the episcopate, and thus the Church of England, as we know it to-day, is the work, so far as its outer form is concerned, of Theodore. His work was determined in its main outlines by the previous history of the English people. The conquest of the Continent had been wrought either by races which were already Christian, or by heathens who bowed to the Christian faith of the nations they conquered. To this oneness of religion between the German invaders of the Empire and their Roman subjects was owing the preservation of all that survived of the Roman world. The Church everywhere remained untouched. The Christian bishop became the defender of the conquered Italian or Gaul against his Gothic and Lombard conqueror, the mediator between the German and his subjects, the one bulwark against barbaric violence and oppression. To the barbarian, on the other hand, he was the representative of all that was venerable in the past, the living record of law, of letters, and of art. But in Britain the priesthood and the people had been driven out together. When Theodore came to organize the Church of England, the very memory of the older Christian Church which existed in Roman Britain had passed away. The first missionaries to the Englishmen, strangers in a heathen land, attached themselves necessarily to the courts of the kings, who were their earliest converts, and whose conversion was generally followed by that of their people. The English bishops were thus at first royal chaplains, and their diocese was naturally nothing but the kingdom. In this way realms which are all but forgotten are commemorated in the limits of existing sees. That of Rochester represented till of late an obscure kingdom of West Kent, and the frontier of the original kingdom of Mercia may be recovered by following the map of the ancient bishopric of Lichfield. In adding many sees to those he found Theodore was careful to make their dioceses co-extensive with existing tribal demarcations. But he soon passed from this extension of the episcopate to its organization. In his arrangement of dioceses, and the way in which he grouped them round the see of Canterbury, in his national synods and ecclesiastical canons, Theodore did unconsciously a political work. The old divisions of kingdoms and tribes about him, divisions which had sprung for the most part from mere accidents of the conquest, were now fast breaking down. The smaller states were by this time practically absorbed by the three larger ones, and of these three Mercia and Wessex were compelled to bow to the superiority of Northumbria. The tendency to national unity which