Constantine I AE follis. 

Obv: CONSTAN-TINVS AVG, laureate head right 
Rev: BEATA TRANQVILLITAS, Altar inscribed VO / TIS / XX in three lines, 
  surmounted by globe, two stars above; C-R across fields
Mintmark: PLG. 

RIC VII Lyons 131, rated R4.

Contributed by Dane for George Clegg (biggyg2), October 2007