The Treaty of Grosswardein or Treaty of Nagyvárad was a secret peace agreement between Ferdinand I

Ferdinand I, Holy Roman Emperor

Ferdinand I was Holy Roman Emperor from 1558 and king of Bohemia and Hungary from 1526 until his death. Before his accession, he ruled the Austrian hereditary lands of the Habsburgs in the name of his elder brother, Charles V, Holy Roman Emperor.The key events during his reign were the contest...

 of the Holy Roman Empire

Holy Roman Empire

The Holy Roman Empire was a realm that existed from 962 to 1806 in Central Europe.It was ruled by the Holy Roman Emperor. Its character changed during the Middle Ages and the Early Modern period, when the power of the emperor gradually weakened in favour of the princes...

 and the John Zápolya signed in Grosswardein / Várad (modern-day Oradea

Oradea

Oradea is the capital city of Bihor County, in the Crișana region of north-western Romania. The city has a population of 204,477, according to the 2009 estimates. The wider Oradea metropolitan area has a total population of 245,832.-Geography:...

, Romania

Romania

Romania is a country located at the crossroads of Central and Southeastern Europe, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea...

) on February 24, 1538. In the treaty the medieval Kingdom of Hungary

Kingdom of Hungary in the Middle Ages

The Kingdom of Hungary was formed from the previous Principality of Hungarywith the coronation of Stephen I in AD 1000. This was a result of the conversion of Géza of Hungary to the Western Church in the 970s....

 was divided by them. Zápolya was recognized as King of Hungary

Kingdom of Hungary

The Kingdom of Hungary comprised present-day Hungary, Slovakia and Croatia , Transylvania , Carpatho Ruthenia , Vojvodina , Burgenland , and other smaller territories surrounding present-day Hungary's borders...

, while Ferdinand retained the western parts of the Hungarian Kingdom

Royal Hungary

The Kingdom of Hungary between 1538 and 1867 was part of the lands of the Habsburg Monarchy, while outside the Holy Roman Empire.After Battle of Mohács, the country was ruled by two crowned kings . They divided the kingdom in 1538...

, and was recognized as heir to the Hungarian throne. John Zápolya was left with the remaining two-thirds of the Kingdom. A short while before Zápolya's death, his wife bore him a son, John II Sigismund Zápolya

John II Sigismund Zápolya

John II Sigismund Zápolya was King of Hungary from 1540 to 1570 and Prince of Transylvania from 1570–1571.-Family:The son of King John I and Isabella Jagiełło, he succeeded his father as an infant...

. Zápolya died in 1540, and John Sigismund was recognized as King of Hungary by the Hungarian nobility. The Ottoman Sultan

Ottoman Dynasty

The Ottoman Dynasty ruled the Ottoman Empire from 1299 to 1922, beginning with Osman I , though the dynasty was not proclaimed until Orhan Bey declared himself sultan...

 Suleyman the Magnificent also recognized John Sigismund as King and as his vassal

Vassal

A vassal or feudatory is a person who has entered into a mutual obligation to a lord or monarch in the context of the feudal system in medieval Europe. The obligations often included military support and mutual protection, in exchange for certain privileges, usually including the grant of land held...

.