Constantius II, 337-361. Medallion of 4 heavy siliquae or 3 light milarenses (Silver, 38mm, 12.61 g 6), Thessalonica, 340-350. FL IVL CONSTANTI-VS PIVS FELIX AVG Draped and cuirassed bust of Constantius II to right, wearing laurel and rosette diadem. Rev. TRIVMFATOR GENTIVM BARBARVM / TES Emperor standing to left, bare-headed and in military dress, holding labarum in his right hand and resting his left on his shield. Cohen 194. Gnecchi 50. RIC 78. Extremely rare. Attractive gray toning. Some minor scratches and rough surfaces from being found in water, otherwise, about extremely fine.
From a German collection, supposedly found in the Rhine some 25 years ago.
Impressive silver coins like this were made for presentation purposes. They were given out by the emperor or his representative on the occasion of anniversaries, victories or any other event when a donative would be appropriate. While these pieces were used as money, they were also kept as mementos by their recipients. This coin could have simply been lost in the Rhine because of accident, but it might be equally likely that it was deliberately thrown into the river as a dedication.