The first wooden manor on the site was constructed for Dukes of Masovia in the 15th century. It was later owned from 1516 by Anna Radziwiłł, Duchess regent of Masovia and Queen Bona Sforza after 1546 for whom an Italian style Renaissance garden was created. The new lavish wooden manor in mannerist style was built in 1570s for Anna Jagiellon. It was here that the premiere of blank-verse tragedy The Dismissal of the Greek Envoys by Jan Kochanowski took place on January 12, 1578. Sigismund III Vasa resided in the manor during the summer. Between 1602 and 1603, according to the Royal accounting books, the old manor was renovated and a new wooden house was built nearby. In 1606 the plan of the manor and garden was prepared for the king by Alessandro Albertini. 

When in 1619 the king purchased the allotments belonging to Augustinian friars the construction of a new brick palace become possible. The spot for a Royal summer palace was chosen approximately 120 meters north from the original manor. According to the cornerstone found in 1972 in the foundations of the eastern wing the construction started on September 16, 1624. The structure was designed by Matteo Castelli and Constantino Tencalla and accomplished after king's death by his son Ladislaus IV Vasa. In 1655 during the so-called Deluge of the Polish-Lithuanian Commonwealth (invasion of allied forces of Sweden from north, Brandenburg from west, Transilvania from south and Muscovy from East), the castle was devastated and remained practically uninhabited till 1668 when it was given to Teodor Denhoff.

​It is a rectangular building with four octagonal towers at the corners, arcaded courtyard and a loggia with a view on Vistula River. Largely destroyed several times, it was reconstructed in 1975. 

Plan of the manor and garden in Ujazdów near Warsaw in 1606 by Alessandro Albertini, scale from. 1: 800, hand drawn multicolored document, 42 × 56 cm (16.5 × 22 in), signed:  Il sito della villa di Jasdovia; Alessandro Albertini, 1606, Archiwum Główne Akt Dawnych w Warszawie, Zb. Kart. 570 – 1.

Cornerstone of the Ujazdów Castle, sandstone, 57 × 57 × 10 cm (22.4 × 22.4 × 3.9 in), inscription in Latin: REGIAE AMOENITATI / SACRA / COELO SOLO LVCO LACV COLLE VALLE / LAETA / PALATIA AESTIVA / FELICIB[us]. FVNDAMENTIS AVSPICATVRV[m.] SAXVM / ANNO D[omi]NI MDCXXIV SEPTEMBR[e] / SIGISMVNDO III POLONIAE XXXVII / CO[n]STANCIA ANNO REGE / POSITVM / ANNO D[omi]NI 1624 DIE 7[septem]BRIS (Devoted Royal delight (...) summer palace), Muzeum Zamku i Szpitala Wojskowego na Ujazdowie​.

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In the beginning of the 17th century the medieval abode of the Dukes of Masovia was largely extended to house the parliament of the Polish-Lithuanian Commonwealth, offices and court of the Vasas. The Italian architects Giovanni Trevano, Giacomo Rodondo, Paolo de la Corte and Mateo Castello constructed a Mannerist-early Baroque five-sided palace between 1598-1619. In 1621-1627, with the threat of Ottoman invasion, the palace was fortified with a curtain wall from the Vistula according to Italian concept of palazzo in fortezza (meaning in Italian, "a palace in a fortress"). Between 1634 and 1637 a large hall was constructed in upper parts of the southern wing to house opera hall of King Ladislaus IV and in 1637 the staircase tower was largely remodelled (Ladislaus' Tower). In 1643 the Prince-Cardinal Charles Ferdinand Vasa's Palace was erected on the northern bastion of the Castle's curtain wall and in 1644 a new gate (Saint John's Gate) and the Sigismund Column were erected by royal architect Constantino Tencalla in Baroque style.

During the so-called Deluge of the Polish-Lithuanian Commonwealth (invasion of allied forces of Sweden from north, Brandenburg from west, Transilvania from south and Muscovy from East), the castle was devastated in three occupations by foreign forces between 1655-1656 (the last was Transilvanian occupation). All valuables, including marble pavements, chimneys and window sills were shipped to Sweden, while the interiors were turned into stables and a hospital.

(1) Detail of the Plan of Warsaw in 1656 by Nicolas Pérelle after Erik Dahlbergh, printed in 1696. The fortifications of the Royal Castle in Warsaw were built in the years 1596-1627 giving the structure the more modern appearance according to principles of the Old Italian School (circle of Antonio da Sangallo). They consisted of a 162-metre-long curtain wall flanked by bastions on either side. Two shorter walls connected the bastions with the Castle. The wall rose at least 6.70 metres above the ground level. The fortifications were made of granite rocks, and due to the instability of the terrain, oak piles were also driven into the ground, the basic material for the surface construction was limestone surmounted with bricks. The remnants of the fortifications were absorbed by subsequent buildings in the 18th-century.

Map legend

• 2. Old Town Hall at the Main Market Square
• 3. Saint John's Cathedral
• 4. Royal Castle
• 5. Courtyard before the castle with Baroque Saint John's Gate
• 6. Sigismund Column
• 7. Medieval Cracow's Gate.

(2) Sigismund III Vasa on catafalque by Christian Melich, 1633, Wawel Royal Castle.

(3-4) The Ladislaus Tower of the Castle, 1637.

Tiles from the excavations in the Royal Castle's garden, 1630s:

(5) Tile with eagles from a stove,

(6) Stove tile with a lion or a griffon,
​
(7) Dutch tile with a soldier.

(1-2) Portrait of Sigismund III Vasa and Constance of Austria by Philipp Holbein II or workshop, ca. 1625, Royal Castle in Warsaw.

​​(3) Portrait of Philip III of Spain by Andrés López Polanco, ca. 1617, Skokloster Castle, possibly from the collection of Sigismund III Vasa. In 1615 Queen Constance of Austria, Sigismund's second wife, ordered the Commonwealth's ambassador in Spain to ask for the portraits of the members of the Spanish Royal family. Her elder sister Margaret of Austria, was a wife of King Philip III of Spain. Since the new Holy Roman Emperor, Matthias, resided more frequently in Vienna then in Prague from 1612, the portraits of Spanish Habsburgs would be sent to Vienna after this date, consequently it is more probable that the Philip III's portrait was captured by Swedish forces in Warsaw and not in Prague.

​(4-5) Portraits of two sisters, daughters of Philip III of Spain and Margaret of Austria: Empress Maria Anna of Spain by Frans Luycx, ca. 1638 and Anne of Austria, Queen of France by Charles Beaubrun, ca. 1645. Both portraits were given to the Visitationist Monastery in Warsaw by John II Casimir Vasa in September 1668 and by most accounts adorned Castle walls.

​(6) Portrait of Eleonora Gonzaga (1630-1686) by Frans Luycx, ca. 1651, Nationalmuseum in Stockholm. A portrait of a relative to Queen Marie Louise Gonzaga and a wife of Emperor Ferdinand III, cousin of John II Casimir Vasa was sent to Warsaw and was captured by Swedes in 1655 (from the collection of Gripsholm Castle).

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