To give a show of fairness and moderation the English ambassadors at Paris lessened their demands more than once, and appeared willing for some time to renew negotiations after their terms had been rejected. But in the end they still insisted on a claim which in point of equity was altogether preposterous, and rejected a compromise which would have put Henry in possession of the whole of Guienne and given him the hand of the French King's daughter Catharine with a marriage portion of eight hundred thousand crowns. Meanwhile Henry was making active preparations for war, and at the same time carried on secret negotiations with the Duke of Burgundy, trusting to have him for an ally in the invasion of France. At length, in the summer of 1415, the King had collected an army and was ready to embark at Southampton. But on the eve of his departure a conspiracy was discovered, the object of which was to dethrone the King and set aside the house of Lancaster. The conspirators were Richard, Earl of Cambridge, Henry, Lord Scrope of Masham, and a knight of Northumberland named Sir Thomas Grey. The Earl of Cambridge was the King's cousin-german, and had been recently raised to that dignity by Henry himself. Lord Scrope was, to all appearance, the King's most intimate friend and counsellor. The design seems to have been formed upon the model of similar projects in the preceding reign. Richard II was to be proclaimed once more, as if he had been still alive; but the real intention was to procure the crown for Edmund Mortimer, Earl of March, the true heir of Richard, whom Henry IV had set aside. At the same time the Earl of March himself seems hardly to have countenanced the attempt; but the Earl of Cambridge, who had married his sister, wished, doubtless, to secure the succession for his son Richard, as the Earl of March had no children. Evidently it was the impression of some persons that the house of Lancaster was not even yet firmly seated upon the throne. Perhaps it was not even yet apparent that the young man who had so recently been a gamesome reveller was capable of ruling with a firm hand a king. But all doubt on this point was soon terminated. The commissioners were tried by a commission hastily issued, and were summarily condemned and put to death. The Earl of March, it is said, revealed the plot to the King, sat as one of the judges of his two brother peers, and was taken into the King's favor. The Earl of Cambridge made a confession of his guilt. Lord Scrope, though he repudiated the imputation of disloyalty, admitted having had a guilty knowledge of the plot, which he said it had been his purpose to defeat. The one nobleman, in consideration of his royal blood, was simply beheaded; the other was drawn and quartered. We hear of no more attempts of the kind during Henry's reign.