the brother or cousin of Magnentius, by whom, after the death of Constans, he was created Caesar, A. D. 351, and raised to the consulship the following year. During the war in Gaul against the Alemanni, Decentius was defeated by Chnodomarius, the leader of the barbarians, and upon this, or some previous occasion, the Treviri, rising in rebellion, closed their gates and refused to admit him into their city. Upon receiving intelligence of the death of Magnentius, to whose aid he was hastening, and finding that foes surrounded him on every side so as to leave no hope of escape, he strangled himself at Sens on the 1 th of August, A. D. 353. The medals which assign to this prince the title of Augustus are deemed spurious by the best authorities. His name appears upon genuine coins under the form MAG. or MAGN. DECENTIUS, leaving it doubtful whether we ought to interpret the contraction by Magnus or Magnentius.
Decentius is called the brother of Magnentius by Victor, de Caes. 42, by Eutropius, 10.7, and by Zonaras, 13.8, 9; the kinsman (consanguineum,-- γένει συναπτομένον) by Victor, Epit. 42, and by Zosimus, 2.45, 54. See also Amm. Marc. 15.6.4, 16.12.5; Fast. Idat:[W.R]