The first princely residence at this location appeared at the turn of the 13th and 14th centuries, approximately coinciding with the foundation of Warsaw. On a hill near the Vistula River, there was already a castellan's hillfort surrounded by a moat at the end of the 13th century. Over the following fifty years, the settlement strengthened and eventually became the residence of the Masovian princes — it was then that the wooden hillfort was transformed into a stone castle. Presumably, in the middle of the 14th century, the oldest surviving part of the building appeared, the so-called Great Tower. The basement and the first floor of this once four-story structure have survived to our days.
In the first decades of the 15th century, thanks to the efforts of Prince Janusz I the Elder in 1407–1410, a three-story stone palace, the so-called Great House (Curia Maior), was constructed here. It housed not only the princely chambers but also a hall which for many years served as the meeting place of the Masovian Sejm.
The most significant transformation of the castle occurred in the second half of the 16th century under the initiative of Sigismund Augustus, when the castle became his residence. The king, who was a collector of art, acquired many fine artworks, some of which are still in the castle. The reconstruction of the castle was entrusted to famous architects of the time: Jakub Parr from Silesia and the Italian Giovanni Battista Quadro, author of the Poznań Town Hall. When the Renaissance architects began their work, the Warsaw Castle consisted of the Great House with the Grodzka Tower, the southern wing, and the Little House. As a result of the reconstructions and modernizations in the second half of the 16th century, the New House with the private chambers of the king was created, the Great House was designated for the Sejm sessions, the Little House was adapted for the needs of Queen Anna Jagiellon (equipped with a spacious dining room and chapel), and the entire complex was given a uniform style. The work of transforming the medieval fortification into a richly decorated royal residence continued in the following years, also under the guidance of Italian architects.
When in 1596 Sigismund III Vasa moved the capital to Warsaw, the castle became the most important building in the state. Over the following years, all the castle buildings were finally unified. In 1632-1648, on the so-called Front Court (now Castle Square), Władysław IV erected a monument in memory of his father, Sigismund III Vasa (Sigismund's Column). The next resident of the castle, King John II Casimir Vasa, refurbished most of the rooms into luxurious Baroque chambers, decorated with tapestries, wall paintings, stucco, and carpets.
1656 is another important date in the history of the Warsaw Castle. It was then that the building was destroyed as a result of the Swedish invasion. First, it was looted, with decor elements, furniture, and artworks being taken, and then it was burned. The ruins of the castle could not serve as a royal residence, so the kings lived in other buildings: John III Sobieski in Wilanów, Augustus III in the Saxon Palace.
The reconstruction of the Royal Castle was only undertaken by Stanisław August Poniatowski in the 1760s. His court architects - Jakub Fontana, Dominik Merlini, and Jan Christian Kamsetzer - rebuilt the castle complex in the neoclassical style. Among the artists responsible for the interior decoration were court sculptor André Le Brun, portrait artist Marcello Bacciarelli, landscape painter Bernardo Bellotto, and decorator Jan Bogumił Plersch. In addition to restoring the destroyed southern wing and creating new decor for the representative halls, the Royal Library was added to the castle ensemble. Although not all of Stanisław August's plans and projects were realized, the castle regained its former importance and was in no way inferior to contemporary royal residences. It was here that the Great Sejm met in 1788-1794, during which the Constitution of May 3, 1791, was adopted.
After the partitions of Poland, the Royal Castle became the residence of the tsarist governors, and then officials. The last significant event for the castle's architecture was the construction of the Kubicki Arcades on the eastern side in 1818-1821, designed by Jakub Kubicki.
After gaining independence in 1920, there was an idea to settle Józef Piłsudski in the castle, but he chose the Belweder as his residence. The state of the castle, as well as other historical buildings in Warsaw, was monitored by the Society for the Care of Monuments of the Past.
During the interwar years, the Royal Castle did not become the official residence of the authorities but served representational purposes. Ceremonial banquets and meetings were held here, hosting high-ranking guests from other countries. The castle witnessed significant historical events: in 1920, Józef Piłsudski was presented with a marshal's baton in Castle Square, from December 17 to 20, the coffin with the body of President Gabriel Narutowicz was displayed in the castle, and in 1926 Ignacy Mościcki took the oath of office as President of the Republic of Poland here. Ignacy Mościcki lived in the castle, where his working offices were located. At the same time, part of the premises already functioned as a museum. Despite its turbulent history and diverse architecture, reflecting various stages and metamorphoses of the royal residence, the castle was considered one of the most important buildings in the country, a symbol of it.
The Royal Castle suffered damage in September 1939, and during the Warsaw Uprising, the Germans blew up what remained of the building. The castle's explosion was a national tragedy, though the destruction of such a facility was predictable - hence the worst consequences were prevented. Castle workers, led by Kazimierz Brokle, and Stanisław Lorenz, the then-director of the capital's National Museum, had previously evacuated a significant part of the artworks, archival documents, furniture, and decorative elements. Brokle became a hero; he died during the castle's shelling on September 17, 1939, a few days after removing the urn with Tadeusz Kościuszko's heart and Queen Bona's prayer book from the building. The secret evacuation of the castle's decorative elements also continued during the occupation. The rescue of the artworks and decorative details is still considered a crucial, including symbolic, element of Polish culture's history during World War II.
After the war, although the castle's reconstruction was deemed a priority, no active steps were taken until 1971. On January 20, 1971, the decision to rebuild the castle was finally made. This was associated with a change of power in Poland - in 1970, Władysław Gomułka gave way to Edward Gierek, who saw political potential in the project: rebuilding such an important city building would undoubtedly meet with a positive response from the masses.
In 1979, the Council of Ministers granted Warsaw's Royal Castle the status of a Monument of History and National Culture. On October 21, 1980, the Old Town, along with the Royal Castle, was added to the UNESCO World Heritage List. The first visitors entered the restored building on August 31, 1984. Many historians and experts consider this day a symbolic end to the post-war reconstruction of Warsaw. However, the work at the castle did not end there. In 1995-2009, the modernized Kubicki Arcades were built. In subsequent years, a castle garden was laid out next to them.
The castle now serves as a museum and is under the jurisdiction of the Ministry of Culture and National Heritage. It also hosts many official visits and state meetings. There are several viewing halls in the castle:
The museum houses exhibitions from different periods. The paintings include landscapes of Warsaw, portraits of famous Polish figures, works by Strobl, Smuglevich, Kaufman, with special emphasis on Rembrandt's paintings "Scholar at the Lectern" and "Girl in a Hat".
A valuable object in the collection is the unique Stockholm Scroll, depicting the Entry of the Wedding Procession of Sigismund III and Archduchess Constance in 1605. The length of this scroll is more than 15 meters.