One of the principal leaders of the conspiracy which had been formed against Richard was the Duke of Buckingham--the same that had taken so active a part in bringing Richard to the throne. What induced him to change sides so suddenly is not certainly known. It is supposed that he was dissatisfied with the rewards which Richard bestowed upon him. At any rate, he now turned against the king, and became the leader of the conspirators that were plotting against him. When the conspirators heard of the death of the princes, they were at first at a loss to know what to do. They looked about among the branches of the York and Lancaster families for some one to make their candidate for the crown. At last they decided upon a certain Henry Tudor, Earl of Richmond. This Henry, or Richmond, as he was generally called, was descended indirectly from the Lancaster line. The proposal of the conspirators, however, was, that he should marry the Princess Elizabeth, Queen Elizabeth Woodville's daughter, who has already been mentioned among those who fled with their mother to the sanctuary. Now that both the sons of Elizabeth were dead, this daughter was, of course, King Edward's next heir, and by her marriage with Richmond the claims of the houses of York and Lancaster would be, in a measure, combined. When this plan was proposed to Queen Elizabeth, she acceded to it at once, and promised that she would give her daughter in marriage to Richmond, and acknowledge him as king, provided he would first conquer and depose King Richard, the common enemy. The plan was accordingly all arranged. Richmond was in France at this time, having fled there some time previous, after a battle, in which his party had been defeated. They wrote to him, explaining the plan. He immediately fell in with it. He raised a small force--all that he could procure at that time--and set sail, with a few ships, from the port of St. Malo, intending to land on the coast of Devonshire, which is in the southwestern part of England. In the mean time, the several leaders of the rebellion had gone to different parts of the kingdom, in order to raise troops, and form centres of action against Richard. Buckingham went into Wales. His plan was to march down, with all the forces that he could raise there, to the coast of Devonshire, to meet Richmond on his landing. This Richard resolved to prevent. He raised an army, and marched to intercept Buckingham. He first, however, issued a proclamation in which he denounced the leaders of the rebellion as criminals and outlaws, and set a price upon their heads.