Seriously angry at the archbishop for binding up his cause with that of the criminous clerks and the usurpation of the Church courts, Henry took the rather unworthy step of endeavouring to bend Thomas to his will by allowing several of his courtiers to bring lawsuits against him, and by threatening to rake up and go through the accounts of all the public monies that had passed through his hands during the eight years that he had been Chancellor. But Becket was not a man to be bullied; he made himself yet more stiff-necked, and assumed the pose of a martyr for the rights of the Church. It was in vain that the other bishops urged him to yield; he attended the Great Council at Northampton in October, 1164, faced the king, refused to submit, and then, pretending that his life was in danger, fled by night and sailed over to Flanders. For the next six years Becket was on the continent, generally under the protection of Henry's suzerain and enemy, the King of France. He was regarded by the continental clergy as the champion of the rights of their order, and treated with the highest respect wherever he went. He did his best to stir up the King of France and his vassals against Henry II., and to induce the Pope Alexander III. to excommunicate him. But Alexander, deep in a quarrel with the great emperor Frederic Barbarossa, did not wish to make an enemy of the strongest king in Western Europe, and refused to do Becket's behest. On his own account, however, the exiled archbishop laid the sentence of excommunication on most of Henry's chief counsellors. As the great body of the bishops sided with the king, Becket's fulminations from over sea had little effect. In England he was treated as non-existent. [Sidenote: =An interdict threatened.--Return of Becket.=] But in 1170 a new complication brought about a change in affairs. King Henry's eldest son and namesake, Henry the younger, was now a lad of fifteen, and his father wished to crown him and take him as colleague in his kingdom. The right to crown an English king was undoubtedly one of the prerogatives of the Archbishop of Canterbury. But Henry left Becket out of account, and caused the ceremony to be performed by Roger of York. This invasion of his privileges wrought Thomas to such fury that he sought out the Pope, and won him over by his vehemence to threaten to lay all England under interdict--to cut it off from Christendom, and forbid the celebration of the Sacraments within its bounds. King Henry, who was engaged in a troublesome war with the French king, was afraid of the consequences of the papal interdict; its enforcement, he thought, would make him too unpopular. So he humbled himself to patching up a truce with Becket, though they could not even yet come to any agreement on the question of the Constitutions of Clarendon. In the autumn of 1170 the king allowed him to return to England, on a tacit agreement that bygones were to be bygones.