He conducted a lifelong campaign against the bearing of coats of arms without lawful authority in accordance with the Law of Arms, whether that authority was a right recognised at the Visitations conducted by heralds between the 16th to 18th centuries or, more commonly, a right deriving from a specific grant entered in the records of the College of Arms. In support of this campaign, he produced a directory which attempted to list all living bearers of arms in England and Wales who could prove such authority, under the title "Armorial Families". This served as an incentive to families who had not got such authority to regularise their position at the College of Arms and the size of the work increased considerably until its final edition in 1929, which remains the most comprehensive published record (the records of the College of Arms being largely unpublished) of post-Victorian heraldry in Britain. Many of the arms were illustrated with specially commissioned heraldic drawings, and Fox-Davies drew on this large resource when illustrating his more systematic treatises on heraldry.