as generally used by ancient Greek authors, consisted of the Greek cities in Southern Italy that were scattered along the shores of Lucania, Bruttii, and Calabria. The cities on the E. coast were built between 735 and 685 B.C. Of these, Sybaris, Crotona, and Metapontum, were founded by the Achaeans; Tarentum by the Spartans; Siris by the Ionians; and Locri Epizephyrii by the Locrians. The Greek cities on the W. coast, with the exception of Rhegium, were of a later date, and, with the exception of that town and Velia, were merely offshoots of the colonies on the E. coast. Thus, Posidonia and Lais were colonized from Sybaris, and Hipponion and Medma from Locri. At an early period the cities of Magna Gracia, as their general title implies, outrivelled in power and prosperity their mother country. As they were, however, descended from distinct races, and were united by no common political interest, their greatness was more apparent than real—more temporary than permanent. They were often at war among themselves, and the rapid advancement of one city was frequently the result of the fall of another. Common danger was the only motive that could league them together. Accordingly, in 393 B.C. they entered into an alliance for mutual protection against the separate attacks of Dionysius of Syracuse and the Lucanians, but were defeated by the former at the River Helorus in 389 B.C. and by the latter near Lais in 390 B.C. Many of the cities of Magna Gracia afterwards fell before the repeated attacks of the Lucanians and Bruttians. Those that survived came under the sway of the Romans after the capture of Tarentum in 272 B.C. At the beginning of the second Punic war, however, they all revolted with the exception of Rhegium. From the severe punishment that followed this revolt they never recovered. In the time of Strabo, Rhegium, Tarentum, and Neapolis alone retained traces of their former Greek civilization.

MAGNETIUS, a Roman emperor of the west, was of barbarian extraction, and rose to the dignity of count under the Emperor Constantine. He afterwards entered the service of Constans; and in A.D. 350, while commanding the troops that defended the banks of the Rhine, he conceived the design of wresting the sceptre from that feeble and indolent prince. With the connivance of Marcellinus, Count of the Sacred Largesses, his plot was matured and carried into execution. That dignitary invited the officers of the army, then stationed near the city of Autun, to a feast in honour of the birthday of his son, and at a late hour of the banquet introduced Magnetius arrayed in the robes and insignia of royalty. The cry of "Long live Augustus" that was raised at this signal by several conspirators, was taken up unconsciously by the excited and astonished guests; and Magnetius forthwith took possession of the imperial palace at Autun. The assassination of Constans followed immediately; and within a short time Gaul, Italy, and the greater part of the western provinces had acknowledged the title of the usurper. After raising a formidable army, Magnentius first attempted, but without success, to negotiate an agreement with Constantine, Emperor of the East, who was already intent upon revenging the death of his brother Constans. He then marched through Italy and Noricum into Pannonia, and in A.D. 351 repulsed the troops of Constantine on the plain of Scissia. In the same year a battle fought before the town of Mursa, on the Drave, ended in the total defeat of Magnentius. A second routing of his forces in the defiles of the Cottian Alps completed his disaster; and when on the eve of being captured by his enemies, he died by his own hand at Lugdunum, in August A.D. 353.