Tom Scott Antiques has dated this piece to the Regency era.

This is a larger mirror than usual and also unusual to have the top full width mirror plate as you tend to find a classical figures plaque here, but this mirror give you a much more effective "reflective" area.
Measuring:
30 3/4” or 78cm high
54 1/2” or 138.5cm wide at the base
2 1/2” or 6.5cm deep at the base
59” or 150cm wide at the cornice
4 3/4” or 12cm deep at the cornice
Tom Scott Antiques has dated this piece to the Regency era.
Specialist dealer in french & english decorative furniture and interiors
You can view the stock and full dealer information on the Tom Scott Antiques Profile Page