Heinemann and Mondschein (Frederick Mont) in provenances of artworks in American museums

The El Greco looted in 1944 by the Nazi Gestapo from Julius Priester passed through Rudolf J. Heinemann, (1901 – February 7, 1975) and the business he owned, Pinakos, and Frederick Mont (aka Fritz Mondschein) and the gallery he owned, Galerie Sanct Lukas, before being identified. The provenance of the looted artwork was falsified, and it took more than seventy years to find it, claim it and obtain restitution (in 2015). 

The obvious question for museums to ask themselves is: which artworks in our collections passed through these individuals or their businesses and are there any provenance gaps or discrepancies that require further verification. 

 The number of questions marks "?" (49) and "probably" (41) and "possibly" (30) and "might have" or "may have" (12) suggests the presence of guesswork and speculation.

Below are a few of the artworks known to have passed through Heinemann or Mont. 

Knoedler's ledgers: mapping missing entry dates and seller names

 

data source: Getty Provenance Index GitHub Knoedler file  13 Dec 2017

(analysis performed  on CSV file before GPI remodel)

Note:  Transactions prior to 1925 or in the Stockbooks 1-7 have been removed from this file, reducing the number of transactions from 40,250 to 13,809.  This enables us to focus on the years 1928 to 1970.

Three huge spikes in activity pop out: 1951, 1928 and 1942. But before we examine what happened in those years to create such a spike, we must deal with a problem of missing data.

Of the above transactions, 1,746 lack an entry date year. That's over 10%! More than even our highest peak!

What to do? Data scientists often "clean" datasets by eliminating rows with incomplete data. That is exactly what we will NOT do. Instead of eliminating these rows of incomplete data from our data set, we will focus on them. 

Why are these 1,746 transactions missing the entry date year? Do they have anything else in common?

What other indicators might supply us with the missing information? Proxies, in short, for the entry date year. (Names associated with specific date ranges, for example).

The Stock Book Numbers 1928-1970

The Stock Book Numbers for transactions with no Entry Date Year

We see that most of the missing years are from Stock Book 11.  

What else can we learn about the profile of the missing dates? We can compare the most frequent nationalities of all transactions 1928-1970 

to the nationalities of the transactions missing entry date years:

The largest contingent are American.  We don't understand this but will file it away, hoping that it might Make sense later.

What about the sellers? And here we are in for a bit of a surprise.

Of the 1,746 transactions that have no entry year, the vast majority - 1,481 - also have no seller.

What kind of ledgers are these that Knoedler was keeping, with neither year nor seller? 

Which ledgers are most concerned by this double absence?

With 1,469 mysterious transactions, it's Stock Book 11. 

Who are the joint owners listed in Book 11 ledger entrees which have no entry date or seller name?

(filter: Joint owner appear at least twice)

Joint Own Auth 1	Count	Knoedler Numbers in Book 11
Pinakos, Inc. (Rudolf Heinemann)	84	A6420, A5321, A4774, A6680, A5326, A5434, A1825, A1834, A1845, A1849, A1943, A1944, A1945, A1946, A2523, A2730, A2770, A2774, A2795, A2964, A3026, A3029, A3044, A3049, A3274, A3292, A3300, A3312, A3527, A5250, A5286, A5467, A5469, A5515, A5624, A5708, A5730, A4542, A4824, A4839, A4840, A4843, A4844, A4849, A4851, A4854, A4898, A4920, A4937, A4940, A4955, A5117, A5213, A5944, A5948, A5960, A5963, A5964, A5965, A5982, A6010, A6122, A6777, A6679, A6593, A6548, A6530, A6501, A6500, A6430, A6415, A6318, A6310, A6299, A6295, A6294, A7059, A6998, A6970, A6932, A7109, A5602, A5603, A6826
Hirschl & Adler Galleries	37	A3815, A4107, A3884, A3886, A3873, A3875, A3876, A3880, A3882, A3883, A3885, A3888, A5284, A5319, A5560, A5561, A5737, A5738, A5788, A5806, A5807, A5928, A6102, A6738, A6727, A6726, A6722, A6721, A6704, A6651, A7047, A7046, A7021, A7005, A7004, A6972, A7125
Spark, Victor David	25	A6144, A3188, A5745, A4448, A4923A, A4923C, A4923D, A4923H, A4923I, A4923K, A4923L, A4923M, A4923O, A4923P, A4923Q, A4923R, A4923S, A4923T, A4923W, A5016, A6013, A6018, A6138, A6145, A6147
Berggruen (Heinz), Galerie & Cie	23	A5750, A6640, A7031, A7030, A7029, A6899, A7119, A7120, A6070, A6073, A6114, A6112, A6150, A7018, A7017, A7016, A7015, A6844, A6843, A6443, A6350, A6347, A6641
Schempp, (Theodore), & Co.	13	A6934, A5188, A6684, A7066, A7002, A7001, A7000, A6942, A6939, A6935, A7116, A7130, A7131
Kennedy Galleries, Inc.	13	A4936, A7127, A7128, A7129, A5581, A6272, A6273, A6274, A7124, A7135, A5074, A5075, A6669
Fine Arts Associates	11	A5304, A5209, A6764, A6739, A7039, A6869, A7114, A7115, A7133, A7134, A6922
The A.B. Closson Jr. Co.	9	A5079, A5080, A5082, A5083, A5085, A5086, A5087, A5088, A5089
Betty McLean Gallery	9	A5288, A5290, A5291, A5292, A5294, A5299, A4684, A4685, A5055
E. and A. Milch	7	A3655, A3855, A3857, A3858, A4635, A6824, A7136
Marlborough-Gerson Gallery	7	A7078, A7080, A7082, A7081, A7083, A7077, A7079
Pearlman, Henry	6	A7086, A7087, A7089, A7090, A7091, A7088
Kleemann Galleries	6	A4617, A6432, A6391, A6390, A6332, A6331
De Hauke & Co.	5	A6763, A7100, A7101, A7103, A7110
Frank Perls Gallery	5	A6506, A6230, A6762, A6743, A6435
Balay, Roland	5	A3834, A3835, A3836, A3837, A3838
Latendorf Bookshop	5	A6249, A6250, A6251, A6252, A6253
Agnew's	5	A5435, A6098, A6099, A6228, A7056
Old Print Shop, The	4	A5714, A5716, A5718, A4672E
Weitzner, Julius H.	4	A6921, A5703, A6534, A6929
Charell, Ludwig	3	A6379, A6378, A6377
Babcock Galleries	3	A3413, A3661, A5072
Galerie les Tourettes (Otto Wertheimer)	2	A5281, A7117
John F. Fleming Rare Book Co.	2	A6388, A6387
Galerie des Arts Anciens et Modernes	2	A6135, A6313
SUTTON, HILDA	2	A3383, A3395
Louis Leon and Co.	2	A6801, A6525
Michelotti, M.	2	A5320, A4049
Ward Eggleston Galleries	2	A5991, A5992
Kernochan, Katherine Lorillard	2	A2144, A2145
Ackermann, (Arthur), and Son	2	A3600, A2556
Frederick A. Stern Inc.	2	A3068, A3206
Weil, (André), Galerie	2	A6701, A6795
STRÖLIN, ALFRED	2	A6478, A6477
Abdy, Robert Henry Edward, Sir, 5th Bart.	2	A7009, A6967
Colnaghi's	2	A1982, A3060

Where else do these Knoedler numbers appear? What do they tell us?

Can the recent publication of the new Getty Provenance Index on linked data principles help us to go further in the analysis of the information that is missing from the original Knoedler ledgers? How might we do this?

tbc...

DATASET: Names in new Getty Provenance Index

 In searching the new Getty Provenance Index, it can be useful to know the "preferred name" as recorded in ULAN, especially when performing a facetted search in the Knoedler files.

Below is a Dataset of names that may be helpful.  The data was retrieved on May 24, 2025. 

The uploaded CSV file contains 61,418 rows and 7 columns. It contains entities (mostly people or organizations) associated with the Getty Provenance Index, particularly those classified as E21_Person or E74_Group in the CIDOC CRM ontology.

Column Name	Description	Non-null Count
URI Linkedart json	The Linked.Art JSON URI for the entity	61,418
name	Preferred name of the person or organization	61,418
ulan	Getty ULAN (Union List of Artist Names) identifier	26,648
starId	Internal Getty Provenance Index identifier (STAR system)	28,500
birthYear	Birth year (if known, usually for people)	15,221
biography	Biographical note or description	10,521

Download Dataset (CSV)

(8.3 MB)

Pinakos Inc joint owner network in the Knoedler files

Pinakos, owned by Rudolph Heinemann, is a name that pops up in Nazi-looted art and false provenances.

However, the Pinakos name has a tendency to be scrubbed from provenance records, replaced either by its owner, Heinemann, or, occasionally, its frequent partner, Knoedler.

This is a pity because while Heinemann and Knoedler operated over long periods of time, including long before WWII, Pinakos is a name that appears only at very specific times. (So specific that it can be used to date undated ledger entrees.)

Pinakos Inc is rarely found alone in the Knoedler ledgers. Usually it appears as a "joint owner". An interesting pattern is Pinakos as first a "joint owner" and then, without the other partner, a seller in a separate ledger entree.

Pinakos Inc often appears in leger entrees "carried forward". Some transactions involve exchanges or returns with several different Knoedler numbers.

This post examines "joint owners" which appear in the Knoedler ledgers together with Pinakos. 

Tips for advanced search and download on the new Getty Provenance Index: VIDEO

The new Getty Provenance Index can be confusing to use. Here are some tips for advanced search and download on the new GPI

https://www.youtube.com/watch?v=Vbf0QjHWQ_8

Demo:
- simple search on Pinakos,
- selection of provenance activity facet
- narrowing to a specific art market actor, (Swiss art dealer Fritz Nathan)
- download into CSV file of the five artworks that Fritz Nathan sold to Pinakos and Knoedler (who acquired jointly)

Tip: Downloading works if you don't select the optional "Export as system values". 

(In the videos I keep the mistakes so that viewer can recognize them and not panic if they make the same.)