Petar IV Zrinski () (6 June 1621 – 30 April 1671) was Ban of Croatia (Viceroy) from 1665 to 1670, general and a writer. A member of the Zrinski noble family, he was noted for his role in the attempted Croatian-Hungarian Magnate conspiracy to overthrow the Habsburgs, which ultimately led to his execution for high treason.
Zrinski family
Petar Zrinski was born in Vrbovec, a small town near Zagreb, the son of Juraj V Zrinski and Magdalena Széchy. His father Juraj VI and great-grandfather Nikola IV had been viceroys or Ban of Croatia, which was then a nominal Kingdom in personal union with the Hungarian Kingdom. His brother was the Croatian-Hungarian general and poet Miklós Zrínyi (Nikola VII Zrinski).
His family had possessed large estates throughout all of Croatia and had family ties with the second largest Croatian landowners, the Frankopan family. He married Ana Katarina, the half-sister of Fran Krsto Frankopan, and they lived in large castles of Ozalj (in Central Croatia) and Čakovec in Međimurje, northernmost county of Croatia. Through his daughter, Ilona Zrínyi (Jelena Zrinska), he was the grandfather of famed Hungarian general Francis II Rákóczi.
Military career
He was initially schooled abroad in Graz and Trnava, and later also studied military science in Italy. Upon his return in 1637, he clashed with the Ottomans near Nagykanizsa. Since then he resided in Ozalj, where he married Ana Katarina Frankapan. Due to forceful seizure of a land parcel near Rijeka, he was accused of treason, but was later pardoned in 1647. He was appointed a great captain of Žumberak uskoks, with whom he participated in the Thirty Years' War, in which he distinguished himself during its final phase on the German and Bohemian frontiers.
In 1649, he defeated an Ottoman army near Slunj, and in 1654, he aided the Republic of Venice both on land and on sea in the Candian War, causing great damage to the Ottomans. In 1655, he again defeated an Ottoman army near Perušić in Lika, which earned him the position of captain of Senj, Ogulin and whole of Primorje (coastline).
On 16 October 1663, he achieved his greatest victory against the Ottomans, in a place called Jurjeve Stjene (George's cliffs), near Otočac, where he defeated a much greater Ottoman army numbering 8,000-10,000 troops under the command of Ali-Pasha Čengić, who was consequently captured by the Croatian army. As a result, the entire army of the Bosnia Eyalet was defeated, and invasions into Gacka from there permanently ceased. In spite of this success, the ransom for Čengić was taken away from him upon the complaint of general Herbert Auersperg, who previously withdrew to Carniola from Karlovac.
Zrinski-Frankopan plot
During the Austro–Turkish War (1663–1664) Petar Zrinski fought the Turks at the siege of Novi Zrin Castle along with his brother Nikola. After the unpopular Peace of Vasvár (1664) between Holy Roman Emperor Leopold I and the Ottoman Empire, he joined Croatian and Hungarian nobility who were disappointed by the failure to remove the Ottomans completely from Hungarian territory and embarked on a conspiracy to remove foreign influence, including Habsburg rule, from the Lands of the Crown of St. Stephen.
Petar Zrinski was involved in the poorly organized rebellion together with his older brother Nikola Zrinski and his brother-in-law Fran Krsto Frankopan and Hungarian noblemen. In the preparations of the plot, plans were disrupted by the death of Nikola Zrinski in the woods near Čakovec by a wounded wild boar. Later rumours insisted that he had in fact perished not in this accident but at the hands of murderers loyal to Habsburg rule; nevertheless this claim remained unsubstantiated. Petar succeeded his brother as Ban of Croatia.
The conspirators, who hoped to gain foreign aid in their attempts, entered into secret negotiations with a number of nations: including France, Sweden, the Polish-Lithuanian Commonwealth and the Republic of Venice, even the Ottoman Empire. All such efforts proved unavailing – in fact, the High Porte informed Leopold of the conspiracy in 1666. It turned out, also, that there was at least one pro-Austrian informant among the rebels. As a consequence the plans for an uprising had made little headway before the conspirators were arrested.