I've found an interesting acount on the mansion of Baron Stieglitz, and there is also a short story on Nadejda Mikhailovna Younine:
The English Embankment is one of the city's grand facades, stretching from Senate Square to the shipbuilding wharves. Plots of land on the English Embankment were very expensive, so the mansions and palaces regularly changed hands.
BY ANZHELIKA MYSHKINA
This fate was also shared by No. 68, the mansion of Baron Stieglitz, at the very end of the Embankment almost alongside the shipbuilding works. This plot originally belonged to the English merchant T. Rex and the wife of the Dutch merchant Betling, but by 1830 was already owned by the merchant Ludwig Stieglitz. Later, in 1859-1862, a vast mansion was built to the design of architect A. Krakau for Baron Alexander Stieglitz, the last of the line. The building was as imposing as the family's capital was extensive. The Stieglitzes, immigrants from Germany, found a second homeland in Russia, where they founded their financial empire; you could call them a family of hereditary bankers and entrepreneurs. As early as the 1820s Ludwig Stieglitz was the most prominent banker in the Russian Empire. In 1828 Emperor Nicholas I conferred on him the title of baron. After his father's death, Alexander inherited not only his title but also his handsome capital (18 million roubles in silver). He continued his father's financial dealings, taking an active part in obtaining foreign loans for the Russian Imperial Court. Through the offices of Stieglitz the Russian Government maintained contacts with bankers in Amsterdam, Paris, London and Warsaw.
The scale of Baron Stieglitz' huge mansion was a reflection of his financial clout and his public position. A. Krakau was one of the most fashionable and expensive architects in the city; when the baron charged him with the design and construction of the palace, he granted him full creative freedom and an unlimited budget. His son-in-law, Secretary of State Alexander Polovtsov, wrote in a somewhat peevish tone in his widely-known memoirs: "The owners entrusted the construction to Krakau, much as people order a pair of boots, giving the architect broad scope for his ideas". The architectural tastes of his father-in-law did not find favour with Polovtsov, who was an "admirer" of the work of M. Mesmacher. It was he, not Krakau, who oversaw the decoration of the mansion at 52 Bolshaya Morskaya Street, a present from Baron Stieglitz to his adopted daughter Nadezhda. The gift was on the occasion of the marriage of Nadezhda (1843-1908) to Alexander Polovtsov, and came with the addition of a million roubles in gold. The wedding took place in 1861, when the baron's adopted daughter had reached the age of 18.
It would be appropriate at this point to describe in detail how the illegitimate daughter of Grand Prince Mikhail Pavlovich came to be in the family of the court banker Stieglitz - a story of intrigue and romance. Family legend has it that on one fine summer's day (24 June 1844) a basket was found in some lilac bushes at the Stieglitz dacha in Petrovskoye, and that in the basket on luxurious swaddling lay a delightful baby girl. A note was pinned to the swaddling, stating that the little girl had been born on 10 December 1843 and christened Nadezhda according to the Orthodox faith, her father's name being Mikhail. On the child's neck glittered a chain with an expensive gold cross, adorned with a large pearl. The little girl was given the surname Junina (or Juneva) on account of the date when she was found. In this way, the Stieglitz banking house became "related" to the Russian Imperial family, and a brilliant future and fabulous wealth awaited the fruit of the extra-marital liaison of Grand Prince Mikhail Pavlovich. Nadezhda Mikhailovna Juneva became the sole heir to the Stieglitz fortune, and after the baron's death in 1884 she inherited the majority of his property, as well as his financial capital. His fortune was indeed huge, consisting of 38 million roubles in monetary terms. In accordance with Stieglitz' will 70,000 roubles were assigned for charitable purposes and 100,000 roubles for a children's refuge; all the rest came under the control of Nadezhda Polovtsova and her family (two sons and two daughters). The palace on the English Embankment was left to Nadezhda as her personal property. However, she and her husband did not wish to move to the sumptuous Stieglitz home, preferring to remain in their mansion in Bolshaya Morskaya Street. They soon took the decision to sell the mansion on the English Embankment; the cost, including the works of art it contained, was over three million roubles.
The palace really was spectacular in its magnifence. Designed in the then fashionable Italian palazzo style, it stood out noticeably from the other buildings on the English Embankment by its imposing proportions. The external appearance of the palace has hardly altered since the mid-19th century: the decoration of the facades is quite well preserved, something that cannot, alas, be said of the interior, which suffered badly from the moment the mansion was nationalised in 1917. The main staircase has survived in a comparatively reasonable condition. The palace interiors could be called an encyclopaedia of mid-19th century luxury, their decoration reflecting that era's concepts of stylishness, refinement and richness. It is worth noting that a few years after the completion of the palace, from 1869 to 1872, the owners commissioned watercolours with views of its interiors from the well-known artist Luigi Premazzi (1814-1891). He painted seventeen in all, extraordinarily accurate and expressive; they were put into a single leather-bound album stamped with Baron Stieglitz' coat of arms. Since 1920 the album has been kept in the State Hermitage's Department of Drawing. Premazzi was a true master of interior painting, and thanks to his skill in filigree we can get a fully authentic impression of the rich decor of the rooms. One is struck not only by the sumptuousness of the architectural decoration, but also by the richness of the collections of painting and applied art. The palace itself, as already mentioned, was put on sale. However, such an expensive purchase was not within the compass of many people, and for three years the palace stood empty. It was only in 1887 that the palace was bought by Grand Prince Pavel Alexandrovich, for almost half the asking price - 1.6 million roubles. It was purchased for the Grand Prince's marriage to Princess Alexandra Georgievna, the daughter of the King of Greece. A grand wedding reception was held in the palace on 6 June 1889. From then onwards the palace began to be called the New Pavlovsky Palace. The couple did not make any serious alterations to the decor of the former banker's mansion, though the Grand Prince commissioned the architect N. Sultanov to design a household church, which was consecrated in an Orthodox ceremony.
In 1914 the First World War broke out, followed by the two revolutions that totally changed the life of the Russian Empire. The palace was nationalised in 1917, and its subsequent fate was similar to that of many other palaces and mansions in St. Petersburg. It was used by a variety of organisations, and for many decades in the Soviet period the Stieglitz home was occupied by the major design institute "Soyuzproektverf". Now the future of the palace is still to be decided, but the hope is that careful restoration will heal its wounds and that it will shine in its former splendour.
A link:http://www.whererussia.com/spb/fullarticle?id=5636
Daniela