The Productions menu has a D'Oyly Carte menu tab that indexes each of the original 13 D'Oyly Carte productions. (Thespis was prior to D'Oyly Carte.) Talent pages have been prepared for each of the original principals, and the Talent pages have been linked to the Production pages to create "cast" lists.
You can now see the entire cast list of each of the operas, and you can click on the link for any one of the principals to see their "bio" -- for now, only of the G&S productions in first run. A few productions since the original have also been added along with a few of their stars, so that they can be referenced for some YouTube clips.
Volunteers are welcome for adding additonal production casts -- revivals, American companies, tours, etc. Use the contact form to let me know if you are interested!
Bunthorne, your GSOpera webmaster