From Longman Dictionary of Contemporary EnglishYour/His etc GraceYour/His etc GraceHIGH POSITION OR RANKused as a title when talking to or about a duke, duchess, or archbishop → grace
Examples from the Corpus
Your/His etc Grace• It may rain again, Your Grace.• It is a manifestation of his grace, his gift to those who will receive it.• Now, more than twenty years later, the Breton presbyter had lost none of his grace or his repose. 