The personal offices of the king and the administrative offices of the Royal Court of Poland were located there from the 16th century until the Partitions of Poland. In its long history the Royal Castle was repeatedly devastated and plundered by Swedish, Brandenburgian, German, and Russian armies.
The Constitution of May 3, 1791, Europe's first modern codified national constitution, as well as the second-oldest national constitution in the world, was drafted here by the Four-Year Sejm. In the 19th century, after the collapse of the November Uprising, it was used as an administrative center by the Tsar. Between 1926 and World War II the palace was the seat of the Polish president, Ignacy Mościcki. After the devastation of World War II it was rebuilt and reconstructed.
Today it is a historical and national monument, and is listed as a national museum.
At the end of 13th century, during the Duke's Conrad II of Mazovia reign, the wooden-earthen gord called Smaller Manor (Latin: Curia Minor) was built. The following duke, Casimir I, decided to build here the first brick building at the burg-city's area the Great Tower (Latin: Turris Magna). Between 1407 and 1410, Janusz I of Warsaw built a storeyed gothic brick castle, called Bigger Manor (Latin: Curia Maior). From 1526 (when the last Masovian Dukes - Stanislaus I and Janusz III died) it became the Royal Residence.
Between 1548-1556 the castle was the residence of Queen Bona Sforza, wife of Sigismund I the Old. The following Polish monarch, Sigismund II Augustus, between 1568–1572 was realizing building's reconstruction project, for example renaissance Royal House was added to the Bigger Manor, according to Giovanni's Battista di Quadro project. Jakub Parr, an architect from Silesia, was taking part in this works as well.
In 1595 king Sigismund III Vasa made a decision about the castle's expansion to public functions. Reconstruction in the early Roman baroque style was done between 1598–1619. The Castle was enlarged, and given its present five-sided shape, with an imposing early baroque elevation facing the town, and a high tower known as the Sigismund's Tower.
At the time of the Deluge between 1655–1656 the Royal Castle in Warsaw was plundered. In 1656 during the Swedish and German siege of Warsaw a shot hit Sigismund's Tower spire, which caused it to break and destruct as it fell onto the castle's courtyard.
During the Great Northern War the Castle suffered from Swedish occupation (they barricade at the castle and kept their horses in the opera hall), German bombing from the Praga bank and Krakowskie Przedmieście and several plundering by the Swedish, German and Russian troops (the Tsar Peter I of Russia took to St. Petersburg all the paintings and other artefacts that preserved at the castle).
In the first half of the 18th century, when first August II and then August III, of the Wettin family from Saxony, were elected to the throne of Poland, there were several attempts at fargoing reconstruction of the castle, but these came to nothing. In 1737 on the restrictions of the Polish Parliament, the Italian architect Gaetano Chiaveri designed a new wing facing the Vistula. It was built between 1741 and 1747, under the supervision of a polonised Italian, Antonio Solari. This was an excellent design, which harmonized extremely well with the older parts of the castle buildings.
During the reign of Stanisław August Poniatowski, the last Polish monarch, from 1764 to the third partition of Poland in 1795, the Royal Castle went through a period of greatness. The allocated money from the royal budget as well as the patronage which the king granted artists and the education and artistic taste of the ruler himself allowed for one of the most interesting reconstruction projects of the castle. Quite a few projects were carried out, which were designed by, among others, French architect Victor Louis, Johann Christian Kamsetzer or Efraim Szreger. The baroque-classical interior was carried out on the basis of Jakub Fontana's and Dominico Merlini's projects. From 1773 the floor was thoroughly refurnished and the inside was decorated (D.Merlin and J.Ch.Kamsetzer's projects), for example new royal apartments, such as The Royal Chapel, The Knight Hall (otherwise known as The National Hall) and The Ballroom (Great Assembly Hall) were built. The successful changes made by the King that took place inside the Castle had a very characteristic Polish identity and a high artistic level. Also a new building of the Royal Library was built form scratch, running along the right wing of the Copper-Roof Palace (included in 1776 to the group of castle buildings) measuring 56 × 9 meters.
On 3 May 1791, the 4-year Sejm passed a constitution at The Royal Castle in Warsaw.
During the Napoleonic Wars, the Castle was the residence of Fryderyk August, Duke of Warsaw and King of Saxony. After the collapse of the Polish Insurrection of 1830–1831, the Castle was the seat of the Governors of the Polish Kingdom.
Many reconstruction projects come from the 19th century and were the work of Polish architects, such as: Adam Idźkowski and Jakub Kubicki. Idźkowski's project of 1843 planned a reconstruction of the Royal Castle using decorative forms borrowed from the gothic, renaissance and empiric architecture. It planned the building of a 3rd floor with 7 different size towers, with attics decorated with eagles and antique statues. On the Zygmuntowska and Władysławowska towers the metal roof domes were meant to be removed and replaced with terraces, surrounded by balustrade. On the Vistula side, on the Saxon elevation, Idźkowski planned to put up antique style reliefs, underneath the frieze of the 3 rysalits. And later, on the façade of the 3rd floor Corynthian pilasters. Horizontal rustic belts and iron balconies were meant to decorate both of the Royal Castle's elevation as well as the Copper-Roof Palace. This project, characteristic for its brave architectural forms, was the answer to the new trend of using historical forms in architecture (as opposed to Kubicki's project 20 years prior, stating moderation of forms based on past works of royal architects carrying out projects on the Royal Castle).
At the time of the next Polish national insurrection, in 1863, the square in front of the castle was the scene of patriotic demonstrations that ended in much bloodshed.
The restoration work began in 1915-1939, and accelerated after the end of World War I, when Poland regained its independence in 1918 following 123 year of partitions. The establishments of the Peace of Riga in 1921 let Poland retrieve some of the Castle collection from the USSR (which the Russian authorities took to Russia). The 1920s conservation and reconstruction works ware supervised by an architect and conservator Kazimierz Skórewicz. In 1928, he was replaced by another architect, Adolf Szyszko-Bohusz. Since 1926 the Royal Castle was the Polish president's residence.
In September 1939 the Castle burnt after the German bombing. During Warsaw's occupation the Castle was plundered by the Germans. German scholars, including Professor Dagobert Frey and Dr Joseph Mühlmann, took an active part in the work of destruction. The National Museum was allowed to keep only a few pieces of equipment to describe the losses and secretly document them with photographs. An art historian – Stanislaw Lorentz – was the one who supervised this process. On Hitler's orders, the Castle was due to be blown up at the beginning of 1940. The bomb unit drilled a number of holes to put dynamite in however, it was not (because of the protest of Italy) until after the Warsaw Uprising when this order was carried out.
After its destruction in 1944 on German command orders all that was left of the Castle was the ground floor, the lowest part of the Grodzka Tower and some remains of the Royal Library and Kubicki's Arcades. On 2 July 1949, Sejm put forward a plan of the Castle's rebuilding. However, the project was unpromising, considering the budgetary stringency and differing priorities of the communist authorities. Nevertheless, the Grodzka Gate has been reconstructed from the stone blocks kept in the National Museum during the war. In 1964 the area surrounding the Castle was arranged and in 2 years later the Royal Castle's building has been rebuilt. On 20 January 1971, Sejm decided to restore the Castle again and created the Civil Committee of Rebuilding the Royal Castle in Warsaw. Building works supervised by an architect Jan Bogusławski, were financed in full with money coming from the Polish citizens. The reconstruction in its basic stage (restoration of the Castle to its state from before 1939) was completed in July 1974, however, the re-equipment (furnishings, paintings, works of art) and final works continued until 1988.
The imposing façade, built of brick is 90 m long and faces the Castle Square. At each end of the façade stands a square tower with a bulbous spire, such as found in Russia. The Sigismund's Tower is located in the centre of the main façade, flanked on both sides by the castle. According to some theories this immense tower (60 m high) is inspired by the towers of Smolensk.
Nowadays, the Castle serves as the Museum and is subordinated to the Ministry of Culture and National Heritage. Many official visits and state meetings are held in the Royal Castle, too. Over 500 000 people visit the Royal Castle every year.
These rooms, which belonged to the residence of Sigismund Augustus, are now host to a number of portraits of the Jagiellon dynasty, a royal dynasty originating in Lithuania that reigned in some Central European countries between the 14th and 16th century.
From 16th century onwards, Polish democracy started here. In 1573, amendments to the constitution of the Polish-Lithuanian Commonwealth were written here, with great religious tolerance. Also, during the Deluge in 1652, the liberum veto was established in these rooms, although not carried out until 1669. In 1791, the May Constitution, Europe's first modern codified national constitution as well as the second-oldest national constitution in the world, was drafted here. The decorations in the room are replica's of the originals by Giovanni Battista di Quadro.
In these apartments, king Stanisław August Poniatowski lived. They consist of the Canaletto room, in which several painted views of Warsaw are on display. These were not painted by Canaletto, but rather by his nephew, Bernardo Bellotto. Jean-Baptiste Pillement worked between 1765-1767 on one of his largest projects, the wallpaper. Domenico Merlini designed the adjacent Royal Chapel in 1776. Nowadays, the heart of Tadeusz Kościuszko is kept here in an urn. The Audience Rooms are also designed by Merlini, with four paintings by Marcello Bacciarelli on display. Andrzej Grzybowski took care of the restoration of the room, that included many original pieces.
In 1994 Countess Karolina Lanckorońska donated 37 pictures to the Royal Castle. Collection includes two paintings (portraits) by Rembrandt: The Father of the Jewish Bride (also known as The Scholar at the Lectern) and The Jewish Bride (also known as The Girl in a Picture Frame) both originally in the Stanisław August Poniatowski collection.