The palace was built between 1639-1642 by Lorenzo de Sent for the Grand Crown Chancellor Jerzy Ossoliński in Mannerist style. It was constructed on the plan of an elongated rectangle with two hexagonal towers at garden side of the building. The palace was crowned with a terrace with a balustrade, above which stood the upper part of the great representative hall, covered with a spherical roof. A possible inspiration for the palace's upper pavilion and its characteristic roof was Bonifaz Wohlmut's reconstruction of Queen Anne's Summer Palace in Prague, 1557-1563.

Adam Jarzębski, styling himself as Musician of His Highness Ladislaus IV and manager of the construction of the royal palace at Ujazdów, in his "Short Description of Warsaw" (The Main Road, or a Short Description of Warsaw) from 1643, described the residence of Jerzy Ossoliński:

Facade with statues of four kings, below inscriptions and a brass statue of Poland holding a sickle, with a plow and a sheaf and marble portal (2427-2435), in the middle of a building a hall covered with roof tiles with gilded brass statues in the corners (2445-2450), 

Elongated outbuilding with servant lodgings and a kitchen (2711-2713), stables building opposit with a gate (2720-2725),

Vestibule with marble portals and iron doors of master craftsmanship (2505-2508), and a staircase with a grille and a large, solid lock (2520-2525),

Large dining room (2465) with niches with statues of white marble and a brass statue of a Cupid holding a bow above the door, chandelier and tapestries (2475-2485), with a door to a wine cellar (2491) and a room with silver and gold tableware (2495-2496),

Hall with upper windows and a fireplace of black highly polished marble with equestrian portrait of king Ladislaus IV Vasa on white horse against a battle scene (2527-2538), a row of family portraits by painter Hans (?) Amman, and paintings reproducing the epic tales of the ancestors, including a story of a knight wounded during a jousting tournament who was healed by Saint Anne, other stories and battle scenes, above busts of Roman Emperors of white marble (2553-2570), stucco trees in corners, most probably by Giovanni Battista Falconi, ceiling decorated with figures, animals and floral motifs and a painting depicting coronation of Queen Cecilia Renata of Austria in presence of chancellor Ossoliński, door portals of black marble with portiere tapestries with Topór (the Axe) coat of arms (2575-2600), polished marble floor (2605-2607), 

Lord's chambers with tapestries, French-style parade bed, tables with gold trinkets and silverware and decorative clocks beside the bed, coffers, fireplace adorned with a mosaic (2611-2632),

Cabinet of curiosities in a right side tower with bronze statues of different horses, birds and people (2635-2644), silver plated cupboard-cabinet with gold inscriptions describing the contents of each drawer (2649-2652), marble table with rarities on it (2659-2662), 

Chapel in the left side tower with an altar with an exquisite painting, relics in glass vessels, offered by the Pope, silver coffer reliquary with bones bound by gold chains, wax miniatures, a table with a casket and a door to a staircase (2667-2692).

In 1633 Ossoliński was sent with a diplomatic mission to the Pope in Rome by newly elected monarch of the Polish-Lithuanian Commonwealth, Ladislaus IV Vasa. The King offered him the starostwo of Bydgoszcz, 60,000 zlotys, six horses, a saber (scimitar) worth 10,000 zlotys, five Brussels' tapestries making up the series of the Story of Moses commissioned by King Sigismund Augustus in the 1550s, three of which were given to the Pope, and a construction site in Warsaw.

An event from 1633 is also worth mentioning when Ossoliński, traveling to Rome via Veneto, fascinated by the beauty of one of the villas near Padua, ordered to immediately take its dimensions. He made his entry to Eternal City wearing a żupan, richly embroidered with gold, buttoned up with 20 large buttons with diamonds, gold sabre set with jewels valued at 20,000 Polish zlotys and mounting a Turkish stallion having golden horseshoes and a horse tack set with precious stones.

In 1638 a life-size statue was cast in brass by Gerdt Benning in Gdańsk according to the design by Georg Münch for then the vice-chancellor Jerzy Ossoliński, most probably to his Castle in Ossolin. It is possible that the same workshop created statues to his Warsaw's palace.

Contrary to the Crown Court Marshall Adam Kazanowski, who had a transgender man at his court, the Chancellor Ossoliński kept a transgender woman in his palace: "a boy who thinks he is a girl, and who also wears a dress: He imitates a girl quite well; especially in that, he is very eager of being cuddled", as recounted Jean Le Laboureur in his "Account of the voyage of the Queen of Poland", published in Paris in 1647 (p. 212).

An engraved effigy of the Chancellor by Willem Hondius from 1648 was created after a portrait by Bartholomäus Strobel. It is possible then that Strobel created more painting for Ossoliński, including for his Warsaw's residence. 

In 1645 the chancellor commissioned the silver-ebony altar for the Chapel of Black Madonna of Częstochowa adorned with his coat of arms. The design was most probably by a Royal court artist Giovanni Battista Gisleni, while silver elements were created by the Royal goldsmith Johann Christian Bierpfaff in Warsaw in 1650. 
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The "Inventory of belongings spared from Swedes and escapes made on December 1, 1661 in Wiśnicz" in the Central Archives of Historical Records in Warsaw, lists some of the preserved paintings from Chancellor's rich collection inherited by his daughter Helena Tekla Ossolińska, wife of Aleksander Michał Lubomirski, owner of the Wiśnicz Castle. 30 paintings from Chancellor's collection in the inventory include the paintings by Raphael, Titian, Guido Reni, Guercino, Domenichino, Veronese, Ribera, Albrecht Dürer and Daniel Seghers. There were also there a painting of the Leda and a swan, a gift from the Emperor, a Cupid sharpening his bow, possibly a copy of the famous work by Parmigianino, acquired in Rome, a "large Blessed Virgin Mary, a wreath around her made of fruits, which the angels holds", most probably by duo of Rubens and Jan Brueghel, and a large canvas showing Chancellor's Entry into Rome in 1633.

Ossoliński died in his palace in Warsaw on August 9, 1650, at the age of 55. He was buried in the church of St. Joseph in Klimontów, which he built. His opulent palace in Warsaw was destroyed during the invasion of the Commonwealth by neighbouring countries, known as the Deluge (1655-1660).

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Adam Jarzębski, styling himself as Musician of His Highness Ladislaus IV and manager of the construction of the royal palace at Ujazdów, in his "Short Description of Warsaw" (The Main Road, or a Short Description of Warsaw) from 1643, dedicated to his benefactor Crown Court Marshall Adam Kazanowski, thoroughly described the residence of this baroque celebrity. 
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Kazanowski gained prominence as a close friend and companion of crown prince Ladislaus Sigismund Vasa, who was elected monarch of the Polish-Lithuanian Commonwealth from 1632 as Ladislaus IV. Together with his brother, Stanisław Kazanowski, Adam was raised with crown prince and accompanied him during his attempt to become a Russian Tsar, in the Khotyn war of 1621 and the 1624 to 1625 European voyage. A breakthrough event for Adam was when his elder brother Stanisław, favourite of crown prince, attacked with syphilis was expelled from the court for promiscuity in 1620. Zygmunt Kazanowski, father of both, had great hopes for the relationship of his older son and young Vasa. Faced with the threat of his imminent death, he persuaded the sick to recommend his younger brother to the prince. Both brothers were accused by Jerzy Ossoliński in his Memoirs of organizing "suspicious" amusements for young prince. When the crown prince became king, Adam was showered with gifts and new official titles.

In 1628, at the age of about 29, Kazanowski decided to get married. He chose Elżbieta Słuszczanka, a daughter of wealthy Castellan of Minsk, Aleksander Słuszko, for the future bride. The marriage meant for him not only a substantial dowry, but also valuable connections in the Grand Duchy of Lithuania. Aleksander Słuszko dismissed the suitor, justifying the refusal with his daughter's young age, as Elżbieta was then only 9 years old. However, thanks to the intervention of the crown prince, Aleksander Słuszko changed his mind. The wedding took place in the spring of 1633, when Elżbieta has reached the legal age of 14. Adam, who also became the Grand Pantler of the Crown that year, gained 50,000 zlotys of dowry. In addition, the young couple received 20,000 zlotys from the king and the value of the gifts was estimated at 40,000 zlotys.

When crown prince Ladislaus Sigismund became an adolescent, his father Sigismund III Vasa bought him a wooden mansion of Andrzej Bobola at the Cracow Suburb Street in Warsaw. In 1628, shortly after his return from a journey to Western Europe, the prince ordered Constantino Tencalla a court architect to build him a new palace in the Italian style. Four yers later, in 1632, Ladislaus gave the palace to Kazanowski, which caused serious misunderstanding with his father, and a special Parliament committee was appointed to determine the circumstances behind this gesture. In 1637, Kazanowski enlarged the building, holding to Tencalla's original designs. The new structure was a large four-storied palace with a garden, enormous terrace, central courtyard, copper roofs and tower tops decorated with gilded crowns.

629 verses (1025-1654) of Jarzębski's work portray the lavish mannerist and early baroque palace constructed between 1628 and 1643 in the center of informal capital of the Commonwealth:

Large arsenal filled with cannons, muskets, excellent armors, tents and turkish garments, lances and spears arranged on the walls, field guns, matchlocks and a skin of a lioness (1057-1066),

Long gallery filled with paintings on both sides with nudes above the table, portraits of the King Ladislaus IV Vasa and his wife Cecilia Renata of Austria, painted Ad vivium and noble ladies, stone statue of Atlas supporting the armillary sphere on the table in the middle (1095-1108),

Small arbor room adjacent to gallery with a French window, columns, stone floor and a view of the river Vistula (1121-1127),

Dining room with windows on two storeys, a large chandelier with a clock showing hours, a balcony for musicians and Flemish tapestries woven with golden thread (1131-1153), chairs covered with gilded cordovan, plaques with coat of arms of the Lords and Marshals between windows in upper part and landscape paintings and cordovan in lower part, tile stove (1177-1187), window with a wine lift from basement, a large silver wine vessel of 150 litres on wheels in the shape of Bacchus wearing a wreath, sitting on a barrel and holding a goblet, several other barrels half the size of the main and a silver wine fountain in the middle of the room, silver ewers, pitchers and trays (1188-1214), the King and the Queen, envoys of Muscovy, of Emperor, of the King of Spain, of Turkey, of France and of Persia were entertained here (1162-1171),

Vaulted steam baths near the coach house with two chambers, hot stone, heating house, cold and hot water, copper bathtubs and white benches (1255-1272),

Room on upper floor covered with cordovan, with a fireplace, marble portals with gold inscriptions, statues in overdoor (1305-1318) and muskets on the walls (1323),

Rooms with paintings and tapestries: animalistic paintings and still-lifes with vegetables by master painters in the first, next room with staircase, seascapes and paintings of ships, casket regals, a harpsichord, a lute, a violin, cymbals, a viol and a harp and doors hung with portieres (1325-1343), next room with live animals, monkey on a chain, white parrot, singing birds in cages, still life paintings with fruits and wines, tapestries, a fireplace and a marble table (1349-1364), 

Lord's bedroom with a table, a painting of Adam and Eve, a bed against tapestries, good paintings, a fireplace and marble floor, a folding bench with wheels (1381-1392), trellis giving to the chapel, altar with gilded grille and a window to the ladies' room (1365-1376),

Lord's study with a mirror, angels' statues holding candles, paintings, tapestries and polished marble floor (1407-1418),

Library with foreign books in different languages, khanjar daggers on the table, daggers set with turquoises, gold bowls and rock crystal vessels (1425-1431),

Lady's rooms, in one of them tortoiseshell caskets, pendant paintings, one with an old man with a sore eye, tapestries and looms (1437-1449), bedroom covered with goldcloth, a draped bed made of a rich fabric, mirror in silver frame above the table, the other in gold plated frame, automaton clock with a man, paintings in ebony frames, marble floor and marble table (1457-1469), a bedroom with a bed of green goldcloth with fringe and a portrait of mother of Her Majesty, Zofia Konstancja Zenowicz, in the next room in the corner of the palace a portrait of father of Her Majesty, Aleksander Słuszka, in his old age above the door, in both rooms marble fireplaces, tables covered with kilims and marble floors (1473-1495),
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Treasury on the groundfloor, the first room filled with guns: bird shotguns, Turkish trench guns, carabins, muskets and Italian pistols, laid with gold and silver, tables covered with Persian kilims (1508-1520), treasury room with gilded stuff set with turquoises, eastern backswords, gold sabres, gold and gilded saddles and horse tacks, sable coats, large trays and ewers in boxes and antique treasures, snake skin and a turtle from India (1530-1561),

Belvedere room with grille with a view of a garden (1579-1582), wine basement with barrels of wine, mild, sweet and spicy (1590-1596), and a beer basement (1601), in the room above a workshop of Dutch painters (1603-1608), next a room with silverware (1612), and a room with hunting falcons (1613), marble pantry with venison, partridges (1641-1645) and a room of captive Muslim Tatar servants (1649-1651).

Three years later, in 1646, Jean Le Laboureur, a companion of the French Ambassador Extraordinaire to Poland, Renée du Bec-Crespin, comtesse de Guébriant, visited the palace and described it in his "Account of the voyage of the Queen of Poland", published in Paris in 1647. He devoted five pages of his book to the building:

Five or six large chambers and several smaller rooms, filled with silk and gold oriental fabrics, beds of gold fabric, cabinets of uncommon workmanship, tables with different items of gold, silver, amber and stones (p. 211).

Large room with marble floor, as the rest of the lodgings, with a large wine fountain, made of silver in the middle, large platform above the door for the musicians, table with 80 silver-gilt Italian style tazzas (four rows of twenty each) with dried fruit, large pears in sugar, oranges, lemons, melons (p. 213), buffet with extraordinary gold and silver vessels, including Bacchus "of a natural height" sitting on a silver barrel with gold wheels, rock crystal glasses with silver-gilt mountings, Elżbieta Słuszczanka was dancing here with her brother Bogusław Jerzy Słuszka, Court Treasurer of Lithuania and marquis Gonzaga Myszkowski with his wife (p. 214).

Kazanowski, struck by the sudden invasion of gout, welcomed the guests at the staircase of his palace carried in a litter (p. 210), accompanied by 300 armed guards, more than 50 pages dressed in yellow satin and short jackets of blue satin, his wife and her ladies (p. 211).

In one of the chambers Le Laboureur noted "two extraordinarily small female dwarfs who were standing up like a sentry, to guard two small dogs, who were not less dwarf in their species, for they are the size of a mice, and both were resting in a white basket little larger than the hand, on a pillow of perfumed satin", while the ladies of Elżbieta Słuszczanka had a transgender man, a woman who behaved like a man, "for their entertainment" (p. 212). In 1643 Kazanowski also arranged a marriage of dwarfs, "an unheard wedding, full of laughter", according to Albrycht Stanisław Radziwiłł.

Following her visit, Kazanowski and his wife, sent to Madame de Guébriant some small amber cabinets and clocks set with diamonds (p. 212).

Little is known about artistic patronage of the Crown Court Marshall. Among confirmed artists at his court was certain Ezechiel Sykora, born in Litomysl in Czechia in 1622, who latinized his family name to Paritius. After Kazanowski's death in 1649 he left Warsaw and went to Silesia. As a żupnik (manager) of the Royal Salt Mines, he commissioned from Gdańsk engraver Willem Hondius in 1645 a series of views of the Wieliczka salt mine.

Kazanowski had also a book of friendship (album amicorum/Stammbuch), wich was in collection of Edward Rastawiecki in Warsaw in 1853. Small oblong book bind in crimson velvet had 125 parchment leaves and majority of contributions from the years of between 1624 and 1625 of his European journey and a few from 1627 to 1644, mainly of ambassadors of the Spanish Empire. During his stay in Brussels in 1624 with the crown prince he received from infanta Isabella Clara Eugenia a gold medallion set with precious stones on a gold chain. It is possible that he intentionally tried to emulate great validos of his time, Duke of Lerma or Count-Duke of Olivares.

Kazanowski died childless in 1649, leaving all his property to his wife Elżbieta. His opulent palace in Warsaw was destroyed during the invasion of the Commonwealth by neighbouring countries, known as the Deluge (1655-1660).

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