Caracalla came into collision with the Alemanni in the year 213, and the Emperor Maximin, who was a Goth on his father's side, laid waste their territory, in 236. About the latter period, the Franks began to make predatory incursions into Gaul, and the Goths became troublesome to the Romans, on the lower Danube. In 251 the Emperor Decius found his death among the marshes of Dacia, while trying to stay the Gothic invasion, and his successor, Gallus, only obtained a temporary peace by agreeing to pay an annual sum of money, thus really making Rome a tributary power. But the Empire had become impoverished, and the payment soon ceased. Thereupon the Goths built fleets, and made voyages of plunder, first to Trebizond and the other towns on the Asiatic shore of the Black Sea; then they passed the Hellespont, took and plundered the great city of Nicomedia, Ephesus with its famous temple, the Grecian isles, and even Corinth, Argos and Athens. In the meantime the Alemanni had resumed the offensive: they came through Rhætiæ, and descended to the Garda lake, in Northern Italy. The Emperor, Claudius II., turned back this double invasion. He defeated and drove back the Alemanni, and then, in the year 270, won a great victory over the Goths, in the neighborhood of Thessalonica. His successor, Aurelian, followed up the advantage, and in the following year made a treaty with the Goths, by which the Danube became the frontier between them and the Romans. The latter gave up to them the province of Dacia, lying north of the river, and withdrew their colonists and military garrisons to the southern side. Both the Franks and Saxons profited by these events. They let their mutual hostility rest for awhile, built fleets, and sailed forth in the West on voyages of plunder, like their relatives, the Goths, in the East. The Saxons descended on the coasts of Britain and Gaul; the Franks sailed to Spain, and are said to have even entered the Mediterranean. When Probus became Emperor, in the year 276, he found a great part of Gaul overrun and ravaged by them and by the Alemanni, on the Upper Rhine. He succeeded, after a hard struggle, in driving back the German invaders, restored the line of stockade from the Rhine to the Danube, and built new fortresses along the frontier. On the other hand, he introduced into Germany the cultivation of the vine, which the previous Emperors had not permitted, and thus laid the foundation of the famous vineyards of the Rhine and the Moselle. [Sidenote: 300.]