Although under Vespasian probably not more than six legions were stationed on the Danube, their number was subsequently raised by Domitian and Trajan to ten; the two chief commands of Moesia and Pannonia hitherto subsisting were withal divided, the first under Domitian, the second under Trajan, and, as the Dacian was super-added, the whole number of the commanderships on the lower Danube was fixed at five. At the outset, indeed, they seem to have cut off the corner which this stream forms below Durostorum (Silistria)--the modern Dobrudscha--and from the place now called Rassowa, where the river approaches within thirty miles of the sea, in order then to bend almost at a right angle to the north, to have substituted for the river-line a fortified road after the manner of the British (p. 187), which reached the coast at Tomis.[132] This corner, however, was, at least from the time of Hadrian, embraced within the Roman frontier-fortification; for from that time we find lower Moesia, which before Trajan had probably possessed no larger standing garrisons at all, furnished with the three legionary camps of Novae (near Svischtova), Durostorum (Silistria), and Troesmis (Iglitza, near Galatz), of which the last lies in front of that very angle of the Danube. Against the Jazyges the position was strengthened by adding to the upper Moesian camps at Singidunum and Viminacium the lower Pannonian at the confluence of the Theiss with the Danube near Acumincum. Dacia itself was then but weakly garrisoned. The capital, now a colony of Trajan, Sarmizegetusa, lay not far from the chief crossings over the Danube in upper Moesia; here and on the middle Marisus, as well as beyond it in the districts of the gold mines, the Romans chiefly settled; the one legion serving as garrison since Trajan's time in Dacia obtained its headquarters, at least soon afterwards, in this region at Apulum (Karlsburg). Farther to the north Potaissa (Thorda) and Napoca (Klausenburg) were probably also at once taken possession of by the Romans, but it was only gradually that the great Pannono-Dacian military centres pushed farther towards the north. The transference of the lower Pannonian legion from Acumincum to Aquincum, the modern Buda, and the occupation of this commanding military position, fall not later than Hadrian, and probably under him; probably at the same time one of the upper Pannonian legions came to Brigetio (opposite to Comorn). Under Commodus all settlement was prohibited along the northern frontier of Dacia for a breadth of nearly five miles, which must stand connected with the frontier regulations to be subsequently mentioned after the Marcomanian war. At that time also the fortified lines may have originated, which barred this frontier similarly to the upper Germanic. Under Severus one of the legions previously in lower Moesia was brought to Potaissa (Thorda) on the Dacian north frontier. [Sidenote: Dacia an advanced position.]