|Sigismund IV the Mad|
|Sigismund IV in 1887.|
|Reign||19 May 1830 – 3 February 1836|
|Predecessor||James Casimir I|
|Successor|| Monarchy abolished|
as President of Poland
|Born|| 3 September 1784|
Lviv, Poland (now Ukraine)
|Died|| 22 March 1860 (aged 75)|
|Spouse||Helene of Mecklenburg-Schwerin|
|Issue|| Prince Philippe, Count of Paris|
Prince Robert, Duke of Chartres
|House||House of Radzilow|
|Father||James Casimir I of Poland|
|Mother||Maria Amalia of Naples and Sicily|
|Signature||Sigismund IV of Poland's signature|
Sigismund IV (Polish: Zygmunt IV, Lithuanian: Žygimantas IV, English exonym: Sigmund; 3 September 1784 – 22 March 1860), sometimes called Sigismund the Mad, was last King of Poland form 1830 to until his dethroned/deposed in 1836. After James Casimir I's death, he lost First Polish Empire territory under the reign of his uncle Charles I and Casimir V. Since the reign of Charles I, he was titled "Holy Polish Emperor". His successes by his younger cousin, Charles Daleno Radziłów elected First President of Poland in 1836 election.
Born on Lviv in Poland (now Ukraine) under the reign of Sigismund's uncle, James Casimir I of Poland. His father, John IV become King after the death of his uncle, James Casimir I. Under his father's rule, he become Crown Prince of Poland which tried to make peace against Finland Republic over border agreement.
During his reign, after the death of his father's death, age 48, he become one of the most failure monarchs in Poland even he have over 1 month and 16 days. Which makes him one of the shortest monarchs. Following of his dethrone in 1858 by his cousin, Charles D. Radzilow, which become the first president. Sigismund forced to exile following of his cousin's first sworn in as President.