Your Grace or your Grace?

An etiquette question, of sorts: is the Y in "Your Grace" capitalized?

thomasrex...

In Scotland, Torquhil Argyll prefers "Yo, Duke"....but then, he spent
a summer as a cowboy in the US.

Ie. is it "I see Your Grace likes spaghetti" or "I see your Grace likes
spaghetti", to use a silly example...

mjcar...

"Honours & Titles", by HMSO, prefers Your Grace, although it notes that
addressing a Duke this way is rarely done now, because "it could be
taken to imply a hint of subservience". Subservience towards
Archbishops is perhaps still permitted.

Sacha...

Besides which, it is rude to comment on someone's eating habits... ;-)
However, if writing to a Duke it would Your Grace.

ScottyFLL...

Styles of titled individuals are capitalized. His/Her/Your Grace,
His/Her/Your Royal Highness, His/Her/Your Majesty, etc.

If the duke is royal, he is addressed as Your Royal Highness and his
wife likewise (unless she was the Duchess of Windsor -- they had other
words they used for her.)