Although the swords of the officers were thus restored to them, they were themselves still held as prisoners until arrangements could be made for exchanging them. In order, however, that they might all be properly provided for, he distributed them around among his own generals, giving to each Russian officer the charge of a Swedish officer of his own rank, granting, of course, to each one a proper allowance for the maintenance and support of his charge. The Russian generals were severally responsible for the safe-keeping of their prisoners; but the surveillance in such cases is never strict, for it is customary for the prisoners to give their _parole_ of honor that they will not attempt to escape, and then they are allowed, within reasonable limits, their full personal liberty, so that they live more like the guests and companions of their keepers than as their captives. The King of Sweden met with many remarkable adventures and encountered very serious difficulties before he reached his own kingdom, but it would be foreign to the subject of this history to relate them here. As to Mazeppa, he made his escape too, with the King of Sweden, across the frontier. The Czar offered a very large reward to whoever should bring him back, either dead or alive; but he never was taken. He died afterward at Constantinople at a great age. One of the most curious and characteristic results which followed from the battle of Pultowa was the promotion of Peter in respect to his rank in the army. It was gravely decided by the proper authorities, after due deliberation, that in consequence of the vigor and bravery which he had displayed on the field, and of the danger which he had incurred in having had a shot through his hat, he deserved to be advanced a grade in the line of promotion. So he was made a major general. Thus ended the great Swedish invasion of Russia, which was the occasion of the greatest and, indeed, of almost the only serious danger, from any foreign source, which threatened the dominions of Peter during the whole course of his reign. CHAPTER XIV. THE EMPRESS CATHARINE. 1709-1715