Hieronim Ossolià Âski, (born ? â died 1575 or 1576), coat of arms Topór, was a Polish statesman, kasztelan of Sandomierz and Wojnicz, a delegate to the Sejm of 1569 and one of the signatories of the Union of Lublin, which formally united Poland and Lithuania into the PolishâÂÂLithuanian Commonwealth. Ossolià Âski was a Calvinist, and a leader of Protestants in the province of Maà Âopolska during the reign of king Zygmunt August. Ossolià Âski was also one of the leaders of the Executionist movement, which sought to reform 16th century Polish politics.
In his youth, Hieronim was sent by his family to study abroad. During this time, most likely in Germany, he became familiar with Calvinism, converted, and would remain a faithful adherent and advocate for Protestantism throughout his life. He also served under Gian Giacomo Medici in Italy and participated in the taking of Siena.
Ossolià Âski was one of the leaders of the Executionist movement, which sought to reform 16th century Polish politics. As an "Executionist", Ossolià Âski promoted the return of state lands illegally seized by some magnates back to the crown, an increase in the powers of the lesser and medium nobility (szlachta), a curtailment of the rights of the Catholic clergy, enforcement of separation of powers in regard to the holding of public offices, religious tolerance, and reform of public finances.
Ossolià Âski, like most other Executionists was also a strong proponent of the unification between the Grand Duchy of Lithuania and Crown of Poland. He was considered a main force behind the treaty of unification (Union of Lublin) which was established at the 1569 Sejm. Before the treaty was implemented, Ossolià Âski argued that Poland and Lithuania were already technically united through the agreements made between Polish king Wà Âadysà Âaw II Jagieà Âà Âo (originally from Lithuania) and the Grand Duke Vytautas, and was probably the author of a political pamphlet De unione Lithwaniea ("On the Lithuanian Union"). He was one of the signatories of the treaty.
Continuing this political line, Ossolià Âski and other Executionists sought closer political integration between the various provinces of the PolishâÂÂLithuanian Commonwealth that had been established by the 1569 Sejm; Prussia, Lithuania, Ruthenia and "Korona".
Along with Rafaà  Leszczyà Âski, the voivode of Brzeà ÂàKujawski, Ossolià Âski proposed the establishment of a national church in Poland, with king Zygmunt August as its head. The original proposal envisioned the establishment of such a Church with approval from the Papacy, although both Ossolià Âski and Leszczyà Âski were willing to cut all ties with Rome if such approval was not granted. The two politicians made the motion at a Sejm of Piotrków in 1555, but it was not accepted. Three years later, at another sejm, Ossolià Âski unsuccessfully proposed that Catholic bishops were to be prohibited from sitting in the Polish Senate.
In 1573, Ossolià Âski was one of the signatories of the Warsaw Confederation. The confederation issued a document which formally and legally established freedom of religion in the PolishâÂÂLithuanian Commonwealth. While previously religious tolerance was a de facto policy of Poland and the PolishâÂÂLithuanian Commonwealth, the Confederation made it constitutionally de jure. In the same year Ossolià Âski supported the election of Henry of Valois to the throne of Poland and took part in the coronation. Soon, however, Ossolià Âski came to oppose the king and supported his dethronement.
Hieronim was the son of Paweà  Ossolià Âski and Zbigniewa Sà Âupecka. Probably circa 1546 he married Katarzyna Zborowska (of the Zborowski family). They had eight surviving children:
He most likely forced his son, Jan Zbigniew Ossolià Âski, to convert to Calvinism. After his father's death, Jan, as well as several of the other children reverted to Catholicism.
He died around 1576 and was buried in Goà ºlice, in a church which he had converted into a Calvinist Zbór (in PolandâÂÂLithuania and Bohemia a type of Protestant place of worship). His tombstone was sculpted by the Italian-Polish architect Santi Gucci, and had been commissioned by Hieronim himself. It was destroyed during World War I, in 1915, and restored after World War II on the basis of archival photographs.