Is the montglane service real

Answer 1

The Montglane Service (from the book "The Eight" by Katherine Neville) is based on a Chess service that Charlemagne did receive. The service itself is a work of fiction.

This is what Katherine Neville had to say when she was asked the same question you're asking:

"I invented the Montglane Service, but there were many similar chess sets described in the Legend of Charlemagne and other medieval romances. The Charlemagne chess set Llewellyn shows her a picture of (designed much later than Charlemagne's time) is still in the Bibliotheque Nationale in Paris."