Constantine I AE Follis 4.64 grams, 23.28 mm. London. 310-312 AD.  

Obverse: CONSTANTINVS PF AVG, laureate and cuirassed bust right.  
Reverse: PRINCIPI IV-VENTVTIS, Constantine standing left, holding globe and spear; star in right field.

mintmark PLN.  

RIC VI London 222; Sear -.

Courtesy of TimeLine Originals (www.time-lines.co.uk), Nov, 2010