Thus the whole world was again brought into unity. The rest of Constantine’s reign is not very rich in remarkable events. He carried on wars against the Goths and Sarmatians, the latter of whom dwelt in those days from the Theiss to Moravia, whilst the Goths were masters of Dacia. The Sarmatians make their appearance as the lords of vanquished Germans; and these serfs, when arms are put into their hands, take advantage of the opportunity to rid themselves of the yoke. Now were the Sarmatians obliged to apply to the Romans for protection, and they were scattered in all directions under the name of Limigantes: hence a Sarmatian colony as far off as the Moselle, is mentioned by Ausonius. Constantine undoubtedly ruled from the Roman Wall in Scotland to the borders of Khurdistan, and to Mount Atlas, just as Diocletian did. The restoration of the Empire had begun under Diocletian, and it must also have quite recovered under the rule of Constantine and his sons. One great drawback, however, was the very heavy weight of taxation which Diocletian had devised and Constantine had completed, and the system of indictions. A province was valued in the lump, and assessed at a fixed sum, which was divided into _capita_ (quotas); and these _capita_ were imposed in an arbitrary manner, sometimes several of them on one man, and sometimes one on several persons. The details of this system are not yet sifted as much as one would wish, although Savigny has written a very fine treatise on the subject.[65] The chief revenues were those which were derived from the land-tax, and from personal taxes. These burthens daily became more oppressive as the expense of the army increased, which was more and more composed of mercenaries. It is evident that the value of every kind of produce had now quite fallen off, and with this the complete change of the monetary system was connected. In the third century, silver of a very bad standard was coined, but the currency was not changed: the state seems to have paid in bad silver, and to have required gold in exchange at the rate of good old silver. The sesterces are done away with, and henceforth we meet with the _aurei_, which were formerly mentioned only in connexion with the pay of the soldiers, and even then but seldom. This most wretched coinage, of which all the collections of the kind in Europe may afford specimens,—these chiefly belong to the times between Valerian and Probus,—gave occasion for a great deal of counterfeit money, of which the dies and the whole apparatus have every now and then been found in France. The bad money also accounts for the strange story in Aurelian’s life of an insurrection, of which the master of the mint is said to have been the prime mover. Aurelian, in fact, may have tried to bring in again the good currency, whereas the master of the mint, on his side, may have found his profit in the bad money; just as Itzig and others did in the Seven Years’ War. Constantine, however, made the _aureus_