Hieronymus Jaroslaw Łaski

Hieronim Jarosław Łaski
Coat of arms	Korab
Born	September 27, 1496
Died	December 22, 1542
Noble family	Łaski
Spouse	Anna Kurozwęcka
Issue Olbracht Łaski, Barbara, Jadwiga Ciołek
Father	Jarosław Łaski

Hieronymus Jarosław Laski, Lasky, Laszki, Laszky, Laskó, Jeromos, Jerome, Hieronym, Hieronim, (September 27, 1496 – December 22, 1542), was a Polish diplomat born of an illustrious Polish family. Laski was the nephew of Archbishop John Laski and served as palatine of Inowrocław and of Sieradia, Sieradz.

Laski's first important mission was to Paris in 1524, ostensibly to contract an anti-Turkish league with the French king François I, but really to bring about a matrimonial alliance between the French king's second son Henri, afterwards Henry II, and the daughter of the King of Poland Sigismund I, a project which failed through no fault of Laski's. (The oldest French prince, styled the Dauphin, had been engaged years before to Princess Mary of England).

The collapse of the Hungarian monarchy at the Battle of Mohács (1526) first opened up a wider avenue for Laski's adventurous activity. Contrary to the wishes of his own sovereign, Sigismund I, whose pro-Austrian policy he detested, Laski entered the service of Janos Zápolya, the Magyar competitor for the Hungarian throne, thereby seriously compromising Poland both with the Emperor of the Holy Roman Empire and with the Pope. Zápolya despatched him on an embassy to Paris, Copenhagen and Munich for help. France granted Zápolya 20,000 in gold, five thousand of which was to be forwarded immediately, but on Laski's return, he found his patron a refugee in Transylvania, whither he had retired after his defeat by Ferdinand I in the Battle of Tarcal in 1527.

In February 1528, Laski arranged for the king of Hungary, Zápolya, to become a vassal to the Ottoman Empire. Laski went still further, and without the authority for his action concluded a ten years' truce between his old master King Sigismund of Poland and the Porte. He then returned to Hungary at the head of 10,000 men, with whose aid he enabled Zapolya to re-establish his position and defeat Ferdinand at Saros-Patak. He was rewarded with the countship of Zips and the governor-generalship of Transylvania.