How a Historian Got Close, Maybe Too Close, to a Nazi Thief

By the late 1990s, most of the Nazi art experts who helped loot European Jews were either dead or living quiet lives under the radar. Not so Bruno Lohse, who served as the art agent to the Reichsmarschall Hermann Göring, Hitler’s right-hand man.

In 1998, Jonathan Petropoulos, a European history professor at Claremont McKenna College, met Lohse in Munich. An effete, imperious figure standing 6-foot-4 and weighing over 300 pounds at the time, Lohse, who had “inextinguishable self-importance,” as Petropoulos writes, welcomed the chance to regale the American scholar with his war stories. Over the next nine years, they met more than two dozen times.

Lohse would often pull out a box of old photographs and mementos, allowing Petropoulos to peer over his shoulder and to pepper him with questions. When Lohse died in 2007 at 96, he bequeathed that box to Petropoulos, who used it as source material for his new book, “Göring’s Man in Paris: The Story of a Nazi Art Plunderer and His World,” out this month from Yale University Press.

Any relationship between an information-seeking scholar and a former Nazi is bound to be a complicated one, and Petropoulos makes clear in the prologue that he had no intention of befriending Lohse. He acknowledges, however, that he “soon appreciated his charms” and came to enjoy their meetings over liver dumpling soup — which provided the professor with access to a lost world.

“I always tried to keep a certain distance, and there was always an element of a game being played, a cat-and-mouse game,” Petropoulos said in an interview earlier this month. “That game became a little more spirited with time, a little more like catch me if you can.”

In the book, he explains why the conversations were worth pursuing.

“The paper trail for these art plunderers, as for most second-rank figures in Nazi Germany, largely dried up after their interrogations and de-Nazifications in the late 1940s,” Petropoulos writes. “The oral history offered by Lohse and other old Nazis provided one of the few ways to reconstruct the postwar experiences of this cohort.”

Petropoulos used some of this material for his 2000 book, “The Faustian Bargain: The Art World in Nazi Germany,” and, when potentially incriminating information resulted from the luncheons, he writes that he shared it with the F.B.I. and restitution experts at organizations such as the Art Loss Register. This new book brings Lohse into sharper focus, as a personality and axis point from which to explore a network of art dealers, collectors and museum curators connected to Nazi looting, both during and after the war.