Concerning the Wallachs, however, who have played a most important part in Roumanian history, a good deal is known, but much is still obscure and the subject of heated controversy. First as to their origin. Some writers believe them to have been a branch of the Slaves; others think they were the Daco-Roman colonists of Mœsia, who, joining the Slaves, crossed the Danube with them, and that subsequently the fused races were known as Wallachs, who gradually spread themselves northward to the Carpathians. Other historians are silent about them until the foundation of the 'Wallacho-Bulgarian Empire,' and then they simply mention that the two races joined for the purpose of gaining their independence.[123] There are, however, certain historians of the middle agea who accord to them a direct Roman origin and say they were the descendants of the Roman colonists who managed to retain their language and their hold upon the soil throughout the dark ages, and in spite of the irruptions and passage of the barbarian tribes of the north and east. This is now the view generally accepted. As we have freely quoted the opinions of modern writers, many of whom, along with the authorities on which their views are based, are entirely unknown to the bulk of our readers, it is only fair that they should be made acquainted with the views of well-known historians who flourished nearer the time of which we are writing. Anna Comnena says (between 1081 and 1118 A.D.): 'The Emperor Alexius commanded Cæsar Nicephorus to enlist as many soldiers as possible by conscription; but not veterans; new men who had not yet been in campaigns. He instructed him as to the tribes from which he was to select his recruits, namely, from the Bulgarians and from amongst those youths who had become hardened by a pastoral life; who possess no settled habitations, but wander about from place to place; those who, in the vulgar tongue, are called "Wallachs" ("Blachos").' Bonfinius enters into details of their history. He tells how Trajan conquered the Dacians; how the province was evacuated; but that the colonists had multiplied to such an extent that the repeated incursions of barbarians failed to exterminate them; and he adds that they adhere so tenaciously to their language that one would imagine they had fought for that rather than for their lives. 'Who would not be astonished,' he says. 'when he considers the deluges of Sarmatians and Goths, the irruptions of Huns, Vandals, and Gepidæ, the incursions of Germans and Lombards, to find that traces of the Latin tongue should be met with amongst the Dacians and Getæ, whom we now call Wallachs, because they are such good marksmen? The Roumanians are descended from the legions and colonists who were led into Dacia by Trajan and other emperors: they were called Wallachs from Pius of Flaccus (after a German pronunciation), but by us, because they are such good marksmen.'