[A. G. Maisey]

In my opinion this keris is early Jawa.

Difficult to place in time, probably a very knowledgeable Javanese enthusiast might give it as something like Kahuripan, that relates to pre-Majapahit East Jawa,which in my opinion cannot be supported by either historical or monumental evidence, but as a classification rather than a place in time, it might stand. There are things that cannot be appraised from a photograph that would need appraisal before I could give a tangguh classification.

My preference is to relate this blade to the very large Javanese blades from the North Coast that immediately followed the collapse of Majapahit and the migration of smiths to the West.

16th century seems reasonable, this would place in the 1500's, Majapahit collapsed around 1525.

17th century is too late because the Demak/Pajang/Mataram forms were dominant at that time.

15th century is too early because during the 1400's the keris was undergoing change from the old Bethok/Buda form to the Modern Keris that we know now.

Of course, if this keris were to be stripped of dress and given a good clean and then stained, most collectors would give it as Bali, I might even do so myself, and then probably place it in the 19th century. But it is not reasonable to assume a 19th century Balinese blade is going to be dressed in very old, probably damaged, North Coast Jawa dress.

EDIT
Close examination of detail cannot support very early East Jawa such as Kahuripan or Jenggolo, there are features that might be able to be aligned to Majapahit, but it would be difficult to convince most people we were looking at a Mojo blade because nobody living has ever seen one in original condition and known with certainty what they were looking at.

The overall length might prove to be a bit short for the North Coast blades I have in mind, but I think overall I need to stay with North Coast, 1500's:- size, workmanship(garap), details pretty much rule out anything else, and the dress rules out 19th century Bali.