The result was a Franco-Ottoman alliance and as an unintended consequence moved Jeronimo Bassano from Venice to England (see also: Ottoman–Venetian War ).

He increased his family's holdings through purchases (Kostel and Krapina)[4] and royal gifts (Bijela Stijena near Pakrac, Lobor, Novigrad (the permission to build novi grad, i.e. "new towns"), Zsámbék, Perbál, Tök and Fürstenfeld).

[5] After the death of Keglević's son-in-law Gašpar Ernušt in 1540, he assumed ownership of his possessions in Međimurje and stayed in fortified Čakovec Castle[6] but was later forced by Nikola Šubić Zrinski to leave it.

[7] In 1542, he was sentenced as an infidel by the Diet in Pressburg, because of his special agreement with the Ottoman Empire and because of the unlawful ownership of Međimurje.

One of the sons of Petar Keglević moved to Valladolid (see: Conflicts with the Ottoman Empire) and Mehmed-paša Sokolović became Commander of the Imperial Squires and later Grand Vizier.

He was not involved in the dynastic fight between the Habsburgs and the Jagiellonians, although he made the business with George, Margrave of Brandenburg-Ansbach, so that this one pulled back from Hungary and Croatia.