According to the amendments to the Law on Holidays, Memorial Days and Non-Working Days in the Republic of Croatia from November 2011, 30 April marks the Day of the Death of Petar Zrinski and Fran Krsto Frankopan. A memorial day dedicated to the families of Zrinski and Frankopan, symbols of sacrifice for the freedom and justice of the Croatian people and the Croatian homeland, is marked under the motto “He who dies honourably lives forever”.
On 30 April 1671, the leaders of the anti-Habsburg conspiracy, Petar Zrinski and Fran Krsto Frankopan, were executed in Wiener Neustadt. Since the peace treaty, Peace of Vasvár, was seen as utterly unfavourable and disgraceful to their lands’ interests, Frankopan and Zrinski decided to raise a rebel against the King, Leopold I. Croatia and Hungary did not recognize the agreement and hoped to liberate their territories from Turkish rule with the help of the Viennese court. As Vienna prevented them from legally fighting for their rights, Croatian and Hungarian nobles had no choice but to unite and exercise their rights through rebellion. The Vienna court, at the same time, pursued an absolutist and centralist policy, disrespecting the class rights of the Croatian and Hungarian nobility.
Upon learning of the conspiracy, thanks to betrayal from the conspiratorial ranks, King Leopold I brought Croatian nobles to Vienna in 1670 under the pretext of reconciliation. He immediately placed them under house arrest and then transferred them from Vienna to a tower in Wiener Neustadt. After a year-long and illegal investigation, because only the Croatian Parliament could have judged Croatian nobles, they were sentenced to death by beheading and amputation of their right hands for insulting the King and betraying the country. As a special "mercy" towards the convicts, the sentence of amputating their hands was pardoned.
Before the execution, they, like their families, were deprived of nobility, and their estates were confiscated by the state. The Viennese court not only stifled the Zrinski-Frankopan resistance movement, but also destroyed the two oldest and most famous families, which for five centuries, until the mid-seventeenth century, played a prominent role in Croatian history.
Regarding their death, a Venetian envoy wrote: "This is the unfortunate end of two such respectable persons, especially Zrinski was very praised and appreciated, because 60 famous Croatian viceroys or Bans belonged to his family."
The remains of Fran Krsto Frankopan and Petar Zrinski were transferred from Wiener Neustadt and buried in 1919 in the Zagreb Cathedral.