DATASET: Christie's sales in German Lost Art Search Requests for art lost by Jewish collectors

👉 DATASET: Artworks in Lostart.de which passed through Christie's AFTER the Nazi's came to power and before restitution.

Columns indicating the year, place and lot numbers of the Christie's sales have been added to Lost Art information to facilitate processing. 

In the case of multiple passages via Christie's an attempt has been made to list some of them.

To view dataset for Christie's in Lost Art Search Requests here:

👉 https://docs.google.com/spreadsheets/d/e/2PACX-1vQpejN6ZWaZD7PpT2N7tcDK-6VmbZbY3XRKhhPAOKehpZYEmnVYD8nOjaP5cxaOBwVaint13_rSaJ_Q/pubhtml?gid=914898591&single=true

Download CSV:

This dataset aims to facilitate computational network analysis. Please indicate any errors so that they may be corrected. 

Holocaust art research digital tools: Lempertz and artworks listed in the (defunct) Nazi Era Internet Portal

Art provenance research tools:

The Cologne auction house of Lempertz was included in the Art Looting Investigation Unit Red Flag list of names in 1946. In recent times, the name has appeared in connection to several claims for restitution of artworks. Until recently American museums published artworks that had gaps in their provenance 1933-1945 in a database called NEPIP (Nazi Era Provenance Internet Portal) (https://www.aam-us.org/programs/the-nazi-era-provenance-internet-portal-nepip-archive/)

This video shows artworks gathered from NEPIP and other sources that mention the word "Lempertz" in the provenance published by museums. 

Note: Some of the mentions concern the German auction house. Some do not. Some concern transactions prior to 1933, others after 1933. Inclusion on the list does not mean that the artwork was looted or sold in a forced sale, only that it contains a specific word.

Link to database used in video: https://public.flourish.studio/visualisation/9769949/ (Enter the word or name you want to search for in the box)

German sales catalogues published by the Getty Provenance Index and Heidelberg University tend to stop or peter out after 1945, so it is very difficult to use digital tools to analyze Lempertz and other auction sales in the 1950s and 1960s and 1970s when Nazi looted artworks were laundered via auction houses with little scrutiny. 

Gathering mentions of Lempertz (and other auction houses) in museums provenances is one workaround for this lack of transparency.

Link to Getty Provenance Index

https://www.getty.edu/databases-tools-and-technologies/provenance/

Link to CSV file downloaded from old Getty GPI for search on Lempertz

https://docs.google.com/spreadsheets/d/e/2PACX-1vTJweR5KAilTRyV0naGWjbLpXjfCNes52bUms-901DtZv99GWDBfi4HMxJfrOVFWEiRa21MAtmXDl6E/pub?gid=1417510852&single=true&output=csv

Link to Heidelberg University German Sales catalogues

https://digi.ub.uni-heidelberg.de/en/germansales//recherche/volltext.html

(photo credit from MFA, Boston museum, The Cumaean Sibyl Donato Creti (Italian (Bolognese), 1671–1749) about 1730 ACCESSION NUMBER 1984.138 PROVENANCE November 23-25, 1983, anonymous (German private collector) sale, Lempertz, Cologne, lot 1482. 1984, sold by Piero Corsini, New York and London, to the MFA. (Accession Date: April 11, 1984) https://collections.mfa.org/objects/34617/the-cumaean-sibyl

How AI summarizes the work of the Germany Advisory Commission

 The following table, created with the AI document analysis tool NotebookLLM, details the claimants, their persecuted ancestors, the artworks subject to the claim, and the recommendation made by Germany's Advisory Commission, which will shut down in November 2025. (Highlights in yellow added by OAD)

It was created by loading the Commission Reports into NotebookLLM and asking the question: list claimants, their persecuted ancestors, the artworks claimed and the decision of the commission

How accurate is NotebookLLM's summary?

Claimants	Persecuted Ancestor(s)	Artworks Claimed	Decision of the Commission
Heirs of A. B.(Community of Heirs, represented by Dr. D. B.)	A. B. (d. 1938) and his four children (C., D., E., and F.)	Painting Das Zitronenscheibchen(Lemon Slice) (c. 1667) by Jacob Ochtervelt	Recommend the restitution of the painting. This was based exclusively on moral and ethical considerations, not legal assessment. The restitution included the stipulation that if the painting is sold within 10 years, the state of Bavaria is to receive 50% of the proceeds.
Heirs of Laura Baumann (Karl Ernst Baumann, grandson)	Laura Baumann (d. 1940)	Painting Portrait der Familie von Dithfurth by Johann J. August von der Embde	Recommend that the painting remain in the museum, and the claimant be paid €10,000 compensation.
Heirs of George E. Behrens(Community of heirs)	George Eduard Behrens (1881–1956)	Painting Pariser Wochentag (Weekday in Paris) (1869) by Adolph von Menzel	Cannot recommend returning the painting.

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...