This coin from Trier has an H under the bust for the family members of Hercules-- Maximianus and Constantius. RIC says it was issued when "Constantius' British campaign was successfully concluded" This is his campaign against Carausius and Allectus. It also commemorates the beginning of the campaign of Maximianus against the Quinquegentiani in North Africa. Though rated as "common" in RIC, they seem not so common in the wild.
Constantius I
A.D. 296- 297
CONSTANTIVS NOB CAES; laureate head right, H under bust.
GENIO POPVLI ROMANI; Genius standing left, modius on head, naked but for chlamys over left shoulder, right holding patera, left cornucopiae; B in left, Γ in right.
In ex. TR
RIC VI Trier 214a