Lot Essay
Cf. M.Dalton, op.cit. p.195-197 nos. 1359-1365, also C.Oman, op.cit, pls 79,80, also D.Scarisbrick op.cit p.102-103, see also Christie's, Rings from Antiquity to the Present Day, 5 October 1988, lot 369, and Christie’s, 9th October 2012, including the Jurgen Abeler collection of rings, lot 343, for similar rings.