+298. Depopulation.+ The depopulation of Italy under the empire is amply proved. Vespasian moved population from Umbria and the Sabine territory to the plain of Rome.[819] Marcus Aurelius established the Marcomanni in Italy.[820] Pertinax offered land in Italy and the provinces to any one who would cultivate it.[821] Aurelian tried to get land occupied.[822] He sent barbarians to settle in Tuscany.[823] As time went on more and more land was abandoned and greater efforts were made to secure settlers. Valentinian settled German prisoners in the valley of the Po.[824] In the time of Honorius, in Campania five hundred thousand arpents were discharged from the _fiscus_ as deserted and waste. In the third century, if the colon ran away from land which no one would take he was pursued by all the agencies of the law and brought back like a criminal.[825] The colons ran away because the _curiales_, their masters, put on them the taxes which the state levied first on the _curiales_.[826] What was wanted was men. The Roman imperial system had made men scarce by making life hard. Pliny said that the _latifundia_ destroyed Italy. The saying has been often quoted in modern times as if it had some unquestionable authority. It is a case of the common error of confusing cause and consequence. The _latifundia_ were a consequence and a symptom. Heisterbergk[827] thinks that the _latifundia_ were not produced by economic causes, but by vanity and ostentation. The owners did not look to the land for revenue. He asks[828] how a strictly scientific system of grand culture with plenty of labor could ruin any country. Rodbertus[829] thinks that the _latifundia_ went from a grand system to a petty system between the times of the elder and the younger Pliny by the operation of the law of rent. He thinks that there must have been garden culture in Italy at the beginning of the empire, and that the colonate arose from big estates with petty industry and from the law of mortgage. He thinks, further, that the colons, until the fourth century, were slaves, and that their status was softened by the legislation of the fourth century. Heisterbergk thinks that the colonate began in the corn provinces, and that it was, at the beginning of the fourth century, on the point of passing away, but the legislation of the fourth century perpetuated it. He thinks that it was injured, as an institution, by the great increase of taxation after Diocletian. Then legislation was necessary to keep the colons on the land.[830]