337-340 AD., Helena, Constantinopolis mint, AE 4, RIC 34

Helena, AE 4 (15-16 mm), 1,32 g., Constantinopolis 5th officina, 337-340 AD.
Obv.: FL IVL HEL - ENAE AVG , bust right wearing ornamental mantle and necklace, hair elaborately dressed, broad hairband.
Rev.: PAX PV - BLICA• / CONS E (= officina 5) in exergue , Pax standing front, head left, holding branch and transverse sceptre (terminal dot to reverse legend)
RIC VIII, p. 449, # 34 ; C.4 ; LRBC 1047 .

Helena, mother of Constantine I, had died in 328 or 329 AD. Her reappearance on the coinage with reverse Public Peace in 337-340 should be connected to the succession of her three grandchildren Constantine II, Constantius II, and Constans in 337, after the assassination of Dalmatius, Hannibalianus, and other descendants of Constantine I's stepmother Theodora who were regarded as their potential rivals.
See J. P. C. Kent, RIC VIII, pp. 7 and 33.