Assayer Alexander Romanov (1904-1914).
Rectangular with rounded corners, chased overall with vertical and fanned reeding and applied with a silver-mounted diamond-set Imperial double-headed eagle, with cabochon sapphire thumb-piece, measurements 9.5 x 6.5 cm. Weight 162 g.
Compare identical cigarette case (different years) sold at Christie's auction Russian Art, 28/11 2011, auction 8003, catalogue no. 218.