The Emperor had long had a secret kindness for the gallant boy who had dared to defy him, and, in the Archduke Rupert had a warm friend and advocate. But in the old Duke of Bavaria, who held, as before said, so much of the Palatine property, he had a bitter foe. His release became the subject of fierce family discussion. The Emperor hesitated, but, moved by the intercession of France, and by his affection for his brother, decided at last to show mercy. Thereupon, his sister, the Duchess of Bavaria, fell on her knees before him, and passionately entreated him to detain Rupert a prisoner. Again the Emperor wavered, but the Empress, siding with the Archduke, carried the day in Rupert's favour. The boy was offered his liberty on the single condition of never again drawing sword against the Imperial forces. The peremptory commands of King Charles procured Rupert's submission to this condition, which he would fain have disputed. But when his promise was required in writing it was more than he could endure. "If it is to be a lawyer's business let them look well to the wording!" said he scornfully. The Emperor took the hint, and declared himself satisfied with a simple promise, Rupert giving his hand upon it, according to the custom of the country.[10] Though France had been the principal factor in Rupert's release, Sir Thomas Roe had all the credit of it; and to Roe's guidance Elizabeth exhorted her son to submit himself. Rupert obeyed her meekly. He seems indeed to have been in an unusually submissive frame of mind, judging by the letters which he addressed at this time to Roe. The first of these bears the date, "Linz, 21 Aug. 1641." {53} "My Lord! "A little journe a had towards the Count of Kevenheller was the cause that thus long you were without an answer. But now I could not let another occasion pass without giving you very great thanks for your pains, and the affection you show in my business, and to tell you that I leve all the conditions to your disposing, since I know your Lordshippe is my frend, and am assured that you would do nothing against my honor. "And so I rest "Your Lordshippe's most affectioned frend, "RUPERT."[11] The next letter, written a month later, is very curiously humble, coming from the fiery Rupert. "My Lord!