Delmatius was part of Constantine's extended family, in this case one of his nephews. He was made Caesar in 335 but murdered along with several other family members shortly after Constantine died in 337 in a purge engineered by Constantius II (and presumably with the aid and consent of his surviving pbrothers).
RIC 69 AE3/4 Obv: FLDELMATIVSNOBC; Laureate, cuirassed bust right.
Rev: GLORIAEXERCITVS; Two soldiers flanking one standard. Lot sold for $11 11/2/01.