The Presidential Palace () is the official residence of the Polish head of state and president alongside the Belweder Palace, located in Warsaw, Poland. Originally constructed in 1643 as an aristocratic mansion, it was rebuilt and remodelled several times over the course of its existence by notable architects. The current neoclassical palace was completed in 1818.

Throughout its history, the palace was a venue for important historical events in Polish, European, and world history. In 1791, the facility hosted authors and advocates of the Constitution of 3 May 1791, the first modern European constitution. In 1818, the palace began its ongoing career as a governmental structure when it became the seat of the Polish Viceroy (namiestnik) of the autonomous Congress Poland, Józef Zajączek.

Following Poland's resurrection after World War I, in 1918, the building was taken over by the newly reconstituted Polish authorities and became the seat of the Council of Ministers. During World War II, it served as a Deutsches Haus for the country's German occupiers and survived the 1944 Warsaw Uprising intact. After the war, it resumed its function as seat of the Polish Council of Ministers. On 14 May 1955, the Warsaw Pact was signed inside the Presidential Palace between the Soviet Union and the Eastern Bloc countries. Since July 1994, the palace has been the official seat of the president of the Republic of Poland.

History

Palace during Polish-Lithuanian Commonwealth: 1643—1795

Construction of the present-day Presidential Palace in Warsaw was begun in 1643 by Crown Great Hetman Stanisław Koniecpolski, owner of the town of Brody (80 km. east of Lwów) and of numerous latifundia situated in Poland's eastern borderlands; hence the palace's first name was "Pałac Koniecpolskich"—the "Koniecpolski Palace". It was said that he owned so much landed property that he could cross the breadth of the Commonwealth while spending every night in one of his own manors. The palace was not completed in the Hetman's lifetime, as he died unexpectedly in 1646 at his Brody residence, a few weeks after taking a young wife.

thumb|left|Koniecpolski Palace in 1656; it was burned down during the [[Deluge (history)|Deluge]]

The palace's architect was Constantino Tencalla, architect to Poland's King Władysław IV and designer of Sigismund's Column, in front of the nearby Royal Castle, commemorating Sigismund III of Poland. The palace was completed by Koniecpolski's son Aleksander in the style of a baroque residence, imitating those of northern Italy and Genoa. A view of the palace in a Warsaw panorama of 1656 by Erik Dahlberg confirms this.

The next owner of the palace was Jerzy Sebastian Lubomirski—Grand Crown Hetman and Crown Chancellor, and later the leader of a rebellion against the king—who bought the palace from Aleksander Koniecpolski.

In 1674 the palace became, for the next 144 years, the property of the Radziwiłł family.

It was bought from descendants of Jerzy Sebastian Lubomirski—Stanisław Herakliusz Lubomirski and Hieronim Augustyn Lubomirski—by Michał Kazimierz Radziwiłł of the Nieśwież–Ołyka line, whose wife Katarzyna was a sister of King Jan III Sobieski. After her death, her son Karol Stanisław Radziwiłł I began renovation of the palace and tidied up its surroundings. He entrusted this task to the king's architect, Augustyn Locci.

thumb|Radziwiłł Palace in 1762

The next-to-last heir in tail of Nieśwież and Ołyka was Karol Stanisław "Panie Kochanku" Radziwiłł, Voivode of Vilnius, son of Michał Kazimierz "Rybeńko" Radziwiłł. He had inherited huge estates from his father and uncle which made him the wealthiest magnate in Poland in the second half of the 18th century, and one of the richest men in Europe. He leased out the palace to Franciszek Ryx to house a theater which staged plays and threw masked balls. During the Four-Year Sejm of 1788–1792, he invited all the members of the four deliberating estates to dine there daily. Two meals were served every day: breakfast before the day's session, for 300 people, and dinner after the session. One of the most impressive feasts given by him was on St. Catherine's Day, 25 November 1789, the 25th anniversary of King Stanisław August's coronation, and commemorating the Union of Lithuania with the Polish Crown. Four thousand guests were invited, and the feast cost over 2 million zlotys.

thumb|left|[[Carmelite Church, Warsaw|Carmelite Church and Radziwiłł Palace (right) in 1780, painting by Bernardo Bellotto]]

On the night of 2–3 May 1791, a conspiratorial group of members of the Four-Year Sejm who were bent on saving the Commonwealth met at the palace to strategize means to secure the adoption, next day, of the 3 May Constitution. This document is called "the first constitution of its kind in Europe" by historian Norman Davies.

During the partitions: 1795—1918

Karol Stanisław Radziwiłł II died a sick and blind man at age 56. His property was inherited by Dominik, son of his half-brother Hieronim. Dominik, who had been wounded at the Battle of Hanau, died heirless on 11 November 1813. The line of the Nieśwież–Ołyka heirs in tail died out with him.

In 1818 the palace became the seat of the Viceroy of the Polish (Congress) Kingdom (when it acquired the name 'Pałac Namiestnikowski' - the Palace of Namestnik of Kingdom of Poland). The first Viceroy, from 1815, was Józef Zajączek (1752–1820), former aide-de-champ to Hetman Franciszek Ksawery Branicki, deputy to the Four-year Sejm, secretary of the Friends of the Constitution (i.e., of the 3 May Constitution), a division commander during the Polish-Russian War of 1792, hero of the Battle of Zieleńce, a Polish Jacobin, a soldier in Jan Henryk Dąbrowski's legions, a general of Napoleon's. At the last he adopted a servile attitude toward Alexander I, King of Poland and Tsar of Russia, who created him a duke in 1818. Zajączek had lost a leg at the Berezina River and was carried about by his valets in an armchair.

thumb|Grand staircase

Beginning in 1818 the palace was rebuilt in classicist style by the architect Chrystian Piotr Aigner (1756–1841).