. g . ▁the ▁D uk edom ▁of ▁Nor folk , ▁the ▁Ear ld om ▁of ▁Sp encer , ▁or ▁the ▁Ear ld om ▁of ▁Alexander ▁of ▁Tun is ). ▁The ▁precise ▁usage ▁depends ▁on ▁the ▁rank ▁of ▁the ▁peer age ▁and ▁on ▁certain ▁other ▁general ▁consider ations . ▁D uk es ▁always ▁use ▁' of '. ▁Mar qu esses ▁and ▁Ear ls ▁whose ▁titles ▁are ▁based ▁on ▁place ▁names ▁normally ▁use ▁' of ', ▁while ▁those ▁whose ▁titles ▁are ▁based ▁on ▁s urn ames ▁normally ▁do ▁not . ▁Vis count s , ▁Bar ons ▁and ▁L ords ▁of ▁Parliament ▁generally ▁do ▁not ▁use ▁' of '. ▁However , ▁there ▁are ▁several ▁exceptions ▁to ▁the ▁rule . ▁For ▁instance , ▁Scottish ▁vice com ital ▁titles ▁theoret ically ▁include ▁' of ', ▁though ▁in ▁practice ▁it ▁is ▁usually ▁dropped . ▁( Th us , ▁the ▁' Vis count ▁of ▁F alk land ' ▁is ▁commonly ▁known ▁as ▁the ▁' Vis count ▁F alk land ' .) ▁ ▁Geographic ▁association ▁ ▁A ▁territorial ▁design ation ▁is ▁often ▁added ▁to ▁the ▁main ▁peer age ▁title , ▁especially ▁in ▁the ▁case ▁of ▁Bar ons ▁and ▁Vis count s : ▁for ▁instance , ▁Baron ess ▁Th atch er , ▁of ▁K este ven ▁in ▁the ▁County ▁of ▁Lincoln shire , ▁or ▁Vis count ▁Mont gom ery ▁of ▁Al ame in , ▁of ▁H ind head ▁in ▁the ▁County ▁of ▁Sur rey . ▁Any ▁design ation ▁after ▁the ▁comma ▁does ▁not ▁form ▁a ▁part ▁of ▁the ▁main ▁title .