King Ethelbert in 602 arranged a conference of British and Roman bishops on the Severn in Essex.[238:2] At that gathering Augustine with unreasonable rigour and haughtiness demanded conformity; the Britains refused to surrender their independence. To settle the matter Augustine proposed that an appeal be made to a miracle. Accordingly a blind Anglo-Saxon was brought in. The Celtic clergy prayed over him in vain. Whereupon Augustine knelt and prayed, and immediately the blind man was restored to sight,[238:3] but the Celts refused to accept that act as final without the consent of a larger representation in the synod. The next year, therefore, a second council was held at which the persistent Augustine once more demanded conformity to Roman practices and the recognition of papal supremacy, and also requested missionary co-operation, but the Britains, displeased with Augustine's narrow dogmatism and apprehensive of the loss of their freedom, refused to submit. "As you will not have peace with brethren," said the stern Roman monk, "you shall have war from foes; and as you will not preach unto the English the way of life, you shall suffer at their hands the vengeance of death."[239:1] When, ten years later, a wholesale Saxon massacre of British Christians occurred, in which possibly a thousand priests and monks were slaughtered and many churches and monasteries destroyed, further conferences were at an end for fifty years. It was not until 664 that the famous Council of Whitby was called by King Oswy of Northumbria in which Bishop Colman and Bishop Cedd, renowned Celtic divines, defended the British Church; while Bishop Agilbert, and Wilfred, the greatest English ecclesiastic of his time, championed Rome. In the discussion about the correct day for Easter, it was asserted by Wilfred that St. Peter held "the keys to the kingdom of Heaven." The king then asked Colman and the monks with him whether that was true, and they were forced to confess that it was. Consequently, feeling that it was safer to be on the side of Peter, the "doorkeeper," the king decided in favour of the Church of Rome.[239:2] This was a very significant victory for the See of St. Peter, because papal supremacy was now recognised in the British Isles, and likewise for the future of England, because it opened up a channel through which Roman Christian civilisation flowed into the British Isles to influence to a greater or less degree every institution in that country and, later, through the great empire which England was to build up to carry those cultural influences around the world. The work of cementing the Latin and Celtic churches in England into one was completed by Theodorus, the Archbishop of Canterbury (d. 690), and the Venerable Bede (d. 735). Ecclesiastical unity hastened political unity in England[240:1] and developed a common civic life among the divided peoples of the British Isles.[240:2]