321 AD., Constantinus I, Rome mint, Follis, RIC 237.

Constantinus I (Constantine), Rome mint, officina 1, 321 AD.,
Æ Follis (18-19 mm / 3,40 g),
Obv.: CONSTAN - TINVS AVG , laureate head right.
Rev.: D N CONSTANTINI MAX AVG // VOT / XX // R P , around and within a undecorated (?) laurel wreath.
RIC VII, p. 321, # 237 "decorated" (C3) .

thanks to Victor Clark and "otlichnik" for more details and comparison ( http://www.forumancientcoins.com/board/index.php?topic=67237 )