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This is a rare ancient Roman silver Argenteus of emperor Valens, dating to 367 - 375 A.D.
D N VALEN S P F AVG: Bust of Valens, pearl-diademed, draped and cuirassed, right
VICT DD NN AVGG: Two Victories, holding up a shield, inscribed VOT/V/MVLT/X
This coin was minted at Rome in the 2nd Officina, mintmark R(oma) B(eta). It had traveled across the English Channel, being discovered by a metal detectorist in Wiltshire.
Although RIC and RSC use the term "argenteus" for this denomination, it is sometimes referred to as a “heavy siliqua” or a “pre-reform saliqua.” A scarce denomination, seldom offered.
DATE: 367 - 375 A.D.
MINTMARK: RB (Rome)
SIZE: 21.02mm diameter
WEIGHT: 2.73 grams
ATTRIBUTION: RIC IX Rome 9