At his death, his art collection was moved to Nuremberg, Germany, where it became a privately owned treasure of that city and was known as the famous "Praunsche Kabinett".

Included in von Praun's collection of over 250 major paintings were two by Michelangelo, two by Raphael, one by Leonardo Da Vinci, two by Andrea del Sarto, one by Guido Reni, two by Tintoretto, ten by Albrecht Durer, one by Peter Brueghel the elder and one by his son Peter, two by Titian, 17 by Denis Calvaert and many others of equal quality including paintings by Vasari, Lucas Cranach, Caravaggio, Parmigianino, Mantegna, and Jacob Jordaens.

The very large collectin of drawings formed by Paul von Praun was undoubtedly one of the finest to be found in Europe in its time. Among the drawings in the collection were 18 by Michelangelo, 3 by Denis Calvaert, 5 by Annibale Carracci, 4 by Domenichino, 8 by Dosso Dossi, 4 by Andrea Mantegna, 30 by Giulio Romanto, 4 by Albrecht Altdorfer, 4 by Lucas Cranach, 15 by Martin Schongauer, 12 by Parmigianino, 5 by Tintoretto, 4 by Andrea del Sarato, 29 by Raphael, 15 by Durer, and many, many other drawings, including those by Vasari, Titian, Correggio, Veronese, Lucas van Lyden, Gercino and Primaticcio.

The "Praunsche Kabinett" also contained in excess of 4,700 copper and wood engravings by the most famous engravers of the 15th and 16th centuries. Among them was the finest group of Durer prints ever acquired by a private collector -- 104 engravings from coper plates and 350 wood cuts --- all of the "first state". It is easy to understand why this Kabinett was highly prized by art connoisseurs throughout Europe for over 200 years. At von Praun's death in Bologna in 1616 , his entire collection was left to his heirs in Nuremberg as a a "Family Trust" and nothing was added to it thereafter. In 1803, however, much to the dismay of the citizens of the city, it passed into the hands of an art dealer by the name of J.F.Fruenholz (1758-1822), who resold almost the entire collection to Prince Nikolaus Esterhazy (1756-1833) with the exception of some drawings and the models sculpted by Michelangelo. When the 647 pieces bought by the Prince were installed in Vienna, they filled 14 rooms and they were a panorama of the art of Europe -- 194 works from Italian schools, 33 from Spain, 82 from German states, 279 from Lowlands and 59 from France. Unfortuanely, during disturbances in Vienna in the mid-nineteenth century, the major portions (and principal pieces) of the Esterhazy Collection were stolen or sold and in 1870 the remmants were moved to Budapest where they remain today.

About 1803 the Michelangelo terracotta models kept by J.F.Fruenholz passed into the hands of the antiquarian Lt. Col Von Gemmingen of Nuremberg. In 1842 all or most of the models were sold to Professor Haehnel of Dresden, who in 1875 exhibited them at the Fine Arts Building of the Bruhlschen Terrasse in Dresden.

In the same year, at an exhbition in Florence commemorating the fourth century of Michelanglo's birth, a number of the models were also exhibited and, according to the art historian Carl von Lutzow, they "were a wonder". There are many interesting references in the well documented history of the Collection. For instance, Professor Haehnel received numerous offers from collectors to buy the models and even Queen Victoria tried without success to acquire them.

Haehnel died in 1891 and the Collection was inherited by his wife and daughter and then ultimately passed to the ownership of Dr. A.B. Heyer who sold it at public auction at Christie's of London in 1938.

From the time that Paul von Praun formed the collectin of models shortly after the death of Michelangelo until it was sold as individual pieces at Christie's in 1938, the Collection remained intact and in the hands of private owners. At the Christie's sale of the 33 models were sold to 7 different buyers; in excess of one-half (17) are now on exhibit.

Four terracotta models are presently in the Victoria and Albert Museum in London and one is in the Museum of Fine Arts in Houston, Texas. There is also a terracotta plaque from the von Praun group in the Morgenroth Collection at the art gallery attached to the Univeristy of California at Santa Barbara -- a plaquette from Leoni Bottega was after a wax design by Michelangelo. The current location of 11 of the 33 models sold in 1938 is unknown and may be presumed to be lost. We do know that a terracotta model of Michelangelo's Medici Madonna was in the Kaiser-Friedrich Museum in Berlin in Berlin before the WWII, but now lies in fragments as a result of the war. It had previously been sold by Haehnel in 1869. The terracotta model for the left hand of Giuliano de Medici (not in the Christie's sale) was purchased directly from the Heahnel Collection by art collector A. von Bernus of Berlin. This small model was subsquently acquired from the daughter of von Bernus and added to the Canadian Collection.

Apart from the Vancouver Collection presently on exhibit and the model in Houson, no other sculpture by Michelangelo is known to exist on the North American continent. This Collection is the largest in the world in terms of models by the Master hand it is undoubtedly the finest group of his works intended as fragmentary studies of human anatomy. There are, in fact, so few Michelangelo models in existence that the works in the Collection are of the utmost importance in any study of Renaissance working techniques. The models, over 400 years old, are in are remarkable state of preservation. There are only 2 publicly accessible collections of wax and clay models as cerfitifed by experts to be by Michelangelo's hand --the von Praun Collection and the Casa Buonarroti in Florence. The latter numbers 6 genuine and one "attributed" small wax and clay models in the collection. There are also two models in the British Museum which were purchased from the Buonarroti Collection.

While this Collection contains a majority of authenticated works, the point should be made that all 18 models were originally in the von Praun Collection and that von Praun, a contemporary of Michelangeo and an art advisor to kings, had the advice of the best artists of his day and was certanily in a position to verify the origin and genuineness of the models.

The selectivity and the fame of his art collection, for which he managed to acquire amongst other objects a great number of famous drawings which Vasari had collected, shows with what great care he acted.

Writing on the Haehnel-von Praun Collectin of 33 models in 1913, the renowned art historian Heny Thode wrote:

That such a illumination of single parts of the body has been a special peculiarity of Michelangelo's form study, is proven by many of his sketches, many of which must have been made directly after such models. Moreover, the particularity of those sketches is only explained by the Haehnel models. It can escape nobody's notice, that those studies generally have in this characteridtic procedure an importance for the knowledge if the Master's work method. It is only by these studies that the scrupulous preparatory work for his statues (and paintings) which is reported by Vasari and Cellini, is brought into a clear light.

The conscientiuous and detailed perfection of the form in the small models is comparable to the diligent execution of his body models in many of his sketches and demands, the same as these, an admiration which the spectator can hardly put into words.

If we consider that the Master himself has destroyed almost all o his models in the desire to keep traces of his work from the eyes of the people, we cannot be greatful enough to the miraculous chance that this Collection has come into our time"

--Henry Thode, Michelangelos Tommdelle aus der Hahnelschen Sammlung, Monatschefte fur Kunstwissenschft, Vol 6, 1913.