A Swiss Aristocratic Legacy Collection Goes Under Hammer [Updated]

The XX auction of Roma Numismatics (Richard E Beale, Villiers Street, London WC2) has just ended, yielding a lot of bids in some largely-unprovenanced high-end ancient numismatic items. One of them (Lot 463) is now the highest-priced ancient coin in the world. The coin is a a rare gold 'aureus' of the EID MAR type (see Wikipedia for a brief definition). There are currently only three examples in this metal known (there are some 80-100 silver ones known) and of the three, only this one is in private hands. The other two gold examples are in the British Museum (on long-term loan) and one in the collection of the Deutsche Bundesbank collection. Both of the latter have been variously assessed, some saying one or the other is a fake. None of them is grounded in a secure archaeological context.

As for this recently-auctioned one, according to the seller's catalogue it has an intriguing collection history. It is from the collection of the Baron Dominique de Chambrier (who's that?), and before (?) that it was reportedly ("original attestation of provenance included") in the private collection of Bernard de Chambrier (1878-1963) and Marie Alvine Irma von Bonstetten (1893-1968) [of the Sinneringen branch of the family]. Marie appears somehow to have inherited the coin by virtue of being the grand niece of collector and antiquarian Baron Gustave Charles Ferdinand von Bonstetten (1816-1892) [the Valeyres branch of the family], Chamberlain to Ferdinand I, Emperor of Austria. Part of the latter's collection formed the Bernisches Historisches Museum. The dealer's catalogue mentions that "the Musée Romain of Avenches also owns pieces from his collection". But this coin seems to have escaped notice (for example not being mentioned in Herbert A. Cahn’s 1989 study of the issue) until it surfaced in this sale. There is an odd gap in the collection history, if Gustav died in 1892 and Marie was born in 1893, did the collection pass to his (apparently only) daughter Berthe (Berta), 1864 -1930, who in 1882 married Colonel Rudolf, Freiherr (Baron) von Reding-Biberegg (1859-1926)? If so, how did it return to the (and which?) Bonstettens and why?

The coin sold for a record price (Coins Weekly, 'A New Record! The Most Expensive Roman Coin of All Time', Nov 5, 2020)  £2,700,000.

I think these are ugly coins, and really have a lot of questions about them that will hardly be resolved when every time one is found they are deftly whipped onto the market to end up being swallowed by (and hidden away in) an undocumented private collection - as was the case here. 

Interestingly, in the same sale was another coin (Lot 65, Sicily, Naxos AR Tetradrachm, circa 460 BC.) from the same Swiss aristocratic collection, and it also raised a large amount. One wonders whether the rest of the dismembered Bonstetten Collection will be surfacing in a similar manner over the next few years.

Update 5th March 2023

It turns out that the "Bonstetten" collection history was bogus (where is the "attestation"?) and had actually been purchased from someone (see here).