[4][5] After the war, he helped found the Zentralinstitut für Kunstgeschichte, a research center for art historians situated in the former Nazi headquarter building in Munich.
Together with Ernst Gall and some other art historians, he edited volumes 3-6 of the Reallexikon zur deutschen Kunstgeschichte [de].
His most popular book, co-written with his former student, Wolfgang Lotz is the Pelican History of Art's Architecture in Italy, 1400 to 1600, first published in 1974.
In August 2012, the original manuscript of Panofsky's Habilitationsschrift of 1920 was found under other papers in an old Nazi safe used by Heydenreich in Munich's Zentralinstitut für Kunstgeschichte.
[7][8][9] It seems as if Heydenreich, from 1946 to 1970, was in the possession of this important manuscript, which was thought to have been lost forever, but possibly never informed Panofsky about this fact.