Merton College, part of the University of Oxford, functions as the on-screen chapel where George and Charlotte get married. The wedding scene is an important turning point in "Queen Charlotte", marking the coming together of old society and the new Ton, each sat on either side of the aisle.
Merton was one of the first three constituent colleges at the university, founded as early as 1264. Its library, Mob library, is the oldest continuously-functioning library for academics and students in the world. The chapel has been functioning for over 700 years, and twelve out of the fourteen stained glass windows are the originals.
The college is still an active part of the university today, with new students starting each year. That being said, it can also be visited by the public for a small admission fee.