Fantax, a seemingly sinister street tough hiding his face behind a mask to make the committing of crimes easier, is really crime fighting British diplomat Lord Horace Neighbour assigned to the United States.  

Lord Horace, wishing to fight crime, takes on the disguise of Fantax so he can move among criminals and take them down one on one.  

He is assisted in this by Barbara his fiancée and later wife who eventually takes to wearing a costume as well; Murph, his butler; P'tit Louis, a muscular assistant; and in time his children, Barbara and Horace Junior who both become crime fighters when adults called Blackboy and Barbara Tiger.  

Blackboy got a series, while Barbara Tiger missed out by the company that published Fantax going under when their creator died.

The odd thing was this British mystery man was French’s first superhero and it seems his costume might have been based on DC Comics Hourman, who had been bootlegged by another French comic publisher in the late 40s.