Erblande in the context of "Ferdinand I, Holy Roman Emperor"

The Empire of Charles V, also known as the Habsburg Empire, included the Habsburg hereditary lands in central Europe, the kingdoms of Spain, the colonial Spanish Empire, the kingdom of Naples, the Habsburg Netherlands and other territories and principalities across Europe. It is sometimes considered to include, in addition, the kingdoms of Bohemia and Hungary which were held by Charles's brother Ferdinand during his reign. Charles was also Holy Roman Emperor and, as such, was suzerain of the states of the Holy Roman Empire.

The empire was the first to be labelled as "the empire on which the sun never sets", a term used to describe several global empires throughout history. The lands of the empire had in common only the monarch, Charles V, while their boundaries, institutions, and laws remained distinct. Charles's nomenclature as Holy Roman Emperor was Charles V (also Karl V and Carolus V), though earlier in his life he was known by the names of Charles of Ghent (after his birthplace in Flanders), Charles II as Duke of Burgundy, and Charles I as King of Spain (Carlos I) and Archduke of Austria (Karl I). The imperial name prevailed due to the politico-religious primacy held by the Holy Roman Empire among European monarchies since the Middle Ages, which Charles V intended to preserve as part of his (ultimately failed) project to unite Christendom under his leadership.

The Archduchy of Austria (Latin: Archiducatus Austriae; German: Erzherzogtum Österreich) was a major principality of the Holy Roman Empire and the nucleus of the Habsburg monarchy. With its capital at Vienna, the archduchy was centered at the Empire's southeastern periphery.

Its present name originates from the Frankish term Oustrich – Eastern Kingdom (east of the Frankish kingdom). The archduchy developed out of the Bavarian Margraviate of Austria, elevated to the Duchy of Austria according to the 1156 Privilegium Minus by Emperor Frederick Barbarossa. The House of Habsburg came to the Austrian throne in Vienna in 1282 and in 1453 Emperor Frederick III, also the ruler of Austria, officially adopted the archducal title. From the 15th century onward, all Holy Roman Emperors but one were Austrian archdukes and with the acquisition of the Bohemian and Hungarian crown lands in 1526, the Habsburg hereditary lands became the centre of a major European power.

John Sigismund Zápolya or Szapolyai (Hungarian: Szapolyai János Zsigmond; 7 July 1540 – 14 March 1571) was King of Hungary as John II from 1540 to 1551 and from 1556 to 1570, and the first Prince of Transylvania, from 1570 to his death. He was the only son of John I, King of Hungary, and Isabella of Poland. John I ruled parts of the Kingdom of Hungary with the support of the Ottoman Sultan Suleiman; the remaining areas were ruled by Ferdinand I of Habsburg, who also ruled Austria and Bohemia. The two kings concluded a peace treaty in 1538 acknowledging Ferdinand's right to reunite Hungary after John I's death, though shortly after John Sigismund's birth, and on his deathbed, John I bequeathed his realm to his son. The late king's staunchest supporters elected the infant John Sigismund king, but he was not crowned with the Holy Crown of Hungary.

Suleiman invaded Hungary under the pretext of protecting John Sigismund from Ferdinand. Buda, the capital of Hungary, fell to the Ottomans without opposition in 1541, but Suleiman allowed the dowager queen, Isabella, to retain the territory east of the river Tisza on John Sigismund's behalf. Isabella and John Sigismund moved to Lippa (now Lipova in Romania). Before long, they took up residence in Gyulafehérvár in Transylvania (Alba Iulia in Romania). John Sigismund's realm was administered by his father's treasurer, George Martinuzzi, who sought to reunite Hungary under the rule of Ferdinand. Martinuzzi forced Isabella to renounce her son's realm in exchange for two Silesian duchies and 140,000 florins in 1551. John Sigismund and his mother settled in Poland, but she continued to negotiate for John Sigismund's restoration with Ferdinand's enemies.

The term French–Habsburg rivalry (French: Rivalité franco-habsbourgeoise; German: Habsburgisch-französischer Gegensatz) describes the rivalry between France and the House of Habsburg. The Habsburgs headed an expansive and evolving empire that included, at various times, the Holy Roman Empire, the Spanish Empire, Portugal through Iberian Union, Austria, Bohemia and Hungary from the Diet of Augsburg in the High Middle Ages until the dissolution of the monarchy following World War I in the late modern period.

In addition to holding the Austrian hereditary lands, the Habsburg dynasty ruled the Low Countries (1482–1794), Spain (1504–1700) and the Holy Roman Empire (1438–1806). All these lands were in personal union under Emperor Charles V. The expansion of the Habsburgs into western Europe increasingly led to border tensions with the Kingdom of France, which found itself encircled by Habsburg territory. The subsequent rivalry between the two powers became a cause for several conflicts. These include parts of the Anglo-French Wars (1066–1815), the War of the Burgundian Succession (1477–1482), the Italian Wars (1494–1559), the Thirty Years' War (1618–1648), the Nine Years' War (1688–1697), and the succession wars of Jülich (1609–1614), Mantua (1628–1631), Spain (1700–1713), Poland (1733–1736) and Austria (1740–1748).