Here follows a long post summarizing the information I have received from a friend on these helmets. I must admit that I am not at all an expert on this area so I am just quoting the information received from my friend.
There are two helmets.
The helmet with a central ridge which ends in a vertical line was in a German private collection since the early 1970s and was sold at Christies Auction 1584 (Dez. 9th 2005) Lot 339 for $26,400. The lot description was as follows:
„A LATE ROMAN IRON HELMET CIRCA 4TH-EARLY 5TH CENTURY A.D. - Formed of several sections hinged and riveted in place, the domed cap with a brow band off set by horizontal ribs, the two halves of the cap joined to a central ridge by rivets, the nose-guard and ornamental arching brows riveted to the brow band, the cheek-pieces flanged toward the neck and hinged to the brow band, each perforated below the chin, the neck-guard with an everted hemispherical flange hinged to the back of the brow band 11. in. (29.2 cm.) long. Provenance: German Private Collection, acquired in the early 1970s.“
I will refer to this as the “Christies Helmet”.
The helmet with a central ridge which ends in more obtuse angles was in a private collection, and exhibited as part of the Attila und die Hunnen exhibition of the Historisches Museum der Pfalz, Speyer (2007) (catalogue pp. 250). Since the 1980s it was in an US private collection and sold at Hermann Historica München, Auction 59 (April 2010) Lot 67 for 62,000 Euros. The lot description was as follows:
„Lot Nr.67 - A late Roman iron helmet, circa 4th/5th century A.D. Formed of several sections hinged and riveted in place, the domed cap with a brow band off set by horizontal ribs, the two halves of the cap joined to a central ridge by rivets, the nose-guard and ornamental arching brows riveted to the brow band, the cheek-pieces flanged toward the neck and hinged to the brow band, each perforated below the chin, the neck-guard with an everted hemispherical flange hinged to the back of the brow band Height 27.5 cm, Weight 1426 grams. Provenance: American Private Collection, acquired in the 1980s. The present example illustrates the popularisation of a new type of helmet construction. Since it was produced in sections then fitted together, they were more easily mass produced. As Southern and Dixon inform (The Late Roman Army, p. 94), "...at a time of crisis in armament procurement, resulting in the establishment of state arms factories under the Tetrarchy, ridge helmets, with their simple design and easier construction, fitted the pressured requirements of the state, who were more interested in the quantity produced rather than the decorative quality." However, many of these same iron helmets were embellished with silver or silver-gilt. Cf. pls. 7-10 in Southern and Dixon, op. cit.“
I will refer to this as the “HH Helmet”.
My friend has provided x-rays of the Christies Helmet and authorized me to publish them here:
[attachment=8724]LRH1.jpg[/attachment]
[attachment=8725]LRH2.jpg[/attachment]
[attachment=8726]LRH3.jpg[/attachment]
My friend has also personally inspected the Christies Helmet and informed me that both his inspection and the x-rays show nothing which would indicate a forgery. He in particular noted the irregular corrosion pattern. According to him, very few parts of the helmet appear to have been restored and the state of preservation was excellent, in particular there were no apparent traces of deformations. This may be consistent with a find from a grave chamber, storage room or similar environment without substantial earth pressure.
My friend also has x-rays of the HH Helmet but not in electronic form and stated that the preservation is very similar except that approx. 50% of the nose guard and one complete cheek piece are modern. In contrast to the Christies helmet, the HH Helmet also appears to have received some modern surface treatment in the form of abrasive action and possibly a wash with natron sulfides (?)
My friend has discussed his findings with a well-known expert in this area who has also personally seen the HH Helmet and both agreed that there is no indication that either helmet is a modern forgery.
Quote:I see half of the romans at Marle 2015 in one of these...
I would like to have a copy of this helmet. The one which encloses the face nicely is very impressive! The replicas I have seen so far are not quite there yet...
As was mentioned, the only way to truly determine its authenticity is a test of the metal content, and a chemical test of the corrosion would determine whether or not it was natural.
Jens has presented a strong argument for its authenticity, but I personally still have my doubts.
A reconstruction of the helmet would certainly be useful in determining its effectiveness and other characteristics.
As for its dating, all we know about it is that its from a private collection. We have no context in which it was found, ergo we cannot accurately date it to anything more than the 280-410 period (Richborough to River Maas Helmets, all Ridge Helmets).