The first we hear of them is that under a powerful chief Burvista or Boerebestes, they conquered their neighbours, the Boii, Jasyges, and probably other tribes, at the eastern boundary of their territory, driving them from their possessions, and from that time they appear as a distinct nation constantly threatening the safety of the Roman provinces in their vicinity. Julius Cæsar, it is said, proposed to attack them shortly before his death, as they made periodical inroads into the Empire, more especially into Mœsia, the country lying between the Danube and the Balkan mountains, of which the Romans had secured the possession. Every winter, as soon as the Danube was frozen over or blocked with ice, they descended from their mountain fastnesses, crossed the broad stream, and carried fire and sword into the Roman territory. Before the latter people had time to gather their forces, their barbarous enemy had retreated, and, the river being once more open, the Dacians endeavoured to prevent the landing of the Roman troops, or, failing that, they made good their retreat to the mountains, whither the Romans feared to follow them. Nor were the Dacians by any means despicable opponents. Although many of them fought bareheaded and clothed in a light tunic, they were well acquainted with the use of armour, and possessed standards, shields, helmets, breast-plates, and even chain and plate mail, fighting with bows and arrows, spears, javelins, and a short curved sword somewhat resembling a sickle.[80] They fought on horseback as well as on foot, and it is said that they sent showers of poisoned arrows into the ranks of their enemies. Of their further proceedings in war as well as in peace we shall have occasion to speak hereafter. About the year 10 B.C. the Emperor Augustus sent one of his generals, Cn. Lentulus, to punish them for having entered and devastated Pannonia under a chief Kotiso, but the expedition was ineffectual, and for a long series of years they continued to harass the Empire, often threatening to overrun whole provinces. One such enterprise is mentioned by Tacitus:--