The beginning of the autumn marked the end of the season for active operations, and the American squadron withdrew, with a promise to return the next season and do yet more damage,--a calamity which the Bashaw avoided by promptly giving up the American prisoners the next spring, when the Americans, true to their word, returned in greater force. A relief squadron which had been sent out from the United States arrived just at the close of the campaign before Tripoli. It brought out Decatur's commission as a post-captain, as well as lesser promotions for the other young commanding officers. Commodore Preble, on being relieved by Commodore Barron, turned over the Constitution to Decatur, who thus, at twenty-five, commanded what was probably the finest frigate in the world. His rank, however, as the youngest post-captain in the navy did not entitle him to keep her very long, and he was transferred to the Congress, a smart thirty-eight-gun frigate. She was in the squadron of Commodore Rodgers, which, after the humbling of Tripoli, was engaged in bringing the Bey of Tunis to terms. Commodore Rodgers sent Decatur, who was well known to the heads of Barbary powers, to negotiate a treaty with Tunis. The Bey at first refused to receive him. Decatur returned to his ship, which was cleared for action, and sent a message saying that the Bey must decide at once between war and peace. The Bey succumbed immediately, and not only begged for peace, but asked that the Congress should convey a Tunisian envoy to the United States. This was rather more than Decatur had bargained for, particularly as he had to give up a part of his quarters to the Tunisian envoy and his suite. But having succeeded rather better than he expected, Decatur took the party on board and returned to the United States, reaching home in 1805. He was received with praise, admiration, and the highest personal and official favor. He was given good commands, and a few years after he had gone out to the Mediterranean to command a little twelve-gun schooner, he again went out in command of a splendid squadron, his broad pennant flying on the mighty Constitution. He was sent to demand reparation from the Dey of Algiers for certain injuries to American citizens. The American consul went in person to see the Dey, who sat in state, looking through the open window at the formidable force with which Decatur was prepared to enforce his demands. The consul began by saying, significantly, that the squadron was commanded by Commodore Decatur. The Dey, gravely combing his beard with a diamond comb, said: "I know this Decatur. He is the man who burnt the frigate at Tripoli. Hum! Why do the Americans send wild young men to treat with old powers?" Nevertheless, he very promptly gave all the satisfaction demanded by the "wild young man."