This is a gold encrusted pattern Limoges porcelain plate made and decorated by William Guerin of Limoges, France between
1900 to 1932. Guerin did not name their patterns but this type of edging is referred to as gold encrusted.
The lion and HgD is an indication that the set of dinnerware was custom ordered for a family with the lion as their family motto
and the initials HGD as the family monogram, likely part of a wedding gifted set from where the bride was registered. Guerin was also a New York importer, so the set was likely ordered at one of the large department stores in New York. While HGDH (His or Her Grand Ducal Highness) was an abbreviation used for non-reigning members of German royalty, I do not see a connection here. While religious abbreviation of His Grace would bring you to H G, the g would never be lower case, so I have ruled that out. I also do not see expensive French porcelain being used in a diocese. The answer is usually the most simple one, being that this was a piece passed down by descendants of the Bishop.
This plate has a current value of $75.00 retail.
Some sites that I recommend for selling are Varagesale.com, Ioffer.com, OfferUp.com, Ebay and letgo.com.
You can also go to invaluable.com or liveauctioneers.com and search their directory for an auction house near you and consign to them.
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