Italian Renaissance frames, like the painted panels, mirrored glass, bronze or marble reliefs they surrounded, were considered works of art in the own right. They were often designed by such celebrated architects and sculptors as Brunelleschi, Lorenzo Ghiberti and Guglielmo della Porta - as can be seen in his design for a bronze frame - which also shares the same term figures with scrolled capitals and tapering pilasters, and dates from the same period as the present lot (see T. J. Newbery, et al., Italian Renaissance Frames, exh. cat., The Metropolitan Museum of Art, New York, 1990, no. 29).
A renewed interest in classical architecture, both in Florence and Venice, in the early 15th century lead away from the late Gothic frames for panel paintings and towards the more architectural framework - most obviously using both free-standing columns and pilasters and pediments - that would be used throughout the Renaissance. These present mirror frames belong to the group of so-called Tabernacle frames (Newbery, Op. cit, pp. 20-23). With their emphasis on a severe architectural framework, they closely mirror the developments in both ecclesiastic architecture - specifically the design of altarpieces - and domestic architecture with elaborate stucco work on the walls and ceilings.
Conceived as an impressive pair, the present lot would have either been produced in the workshops of Florence or Rome. And the sophisticated design, complex achievement of the carved details and the inclusion of costly hard-stones - which provide an unusually colorful and sumptuous contrast to the gilded surfaces - would have elevated the present pair of frames as a serious contribution to the decorative arts of the Renaissance.