these fractionals are a bit rarer for Constantine, though not hard to get. This example is neat because it is ex-Dattari and some of the patina on the obverse is really blue. When I first got it, I tossed it into the Constantius I category and it was not until after I photographed and looked at the legends that I realized who it was. I suspect this happens every now and again with this type, so probably a few examples out there misattributed to Constantius I.
Constantine I
A.D. 306- 307
Radiate fraction
19x21mm 2.2g
FL VAL CONSTANTINVS NOB CAES; radiate, draped and cuirassed bust right.
CONCORDIA MILITVM; Prince standing right in military dress, receiving Victory on globe from Jupiter l. leaning on scepter; A in center.
In ex. ALE
RIC VI Alexandria 85