Ferdinand I (10 March 1503 – 25 July 1564) was Holy Roman Emperor from 1556, King of Bohemia, Hungary, and Croatia from 1526, and Archduke of Austria from 1521 until his death in 1564.Milan Kruhek: Cetin, grad izbornog sabora Kraljevine Hrvatske 1527, Karlovačka Županija, 1997, Karslovac Before his accession as emperor, he ruled the Austrian hereditary lands of the House of Habsburg in the name of his elder brother, Emperor Charles V, and often served as Charles' representative in developing encouraging relationships with German princes. In addition, Ferdinand also developed valuable relationships with the German banking house of Jakob Fugger and the Castillan bank of Palenzuela's Vienveniste Ha Levi Ha Kahana family.

The key events during Ferdinand's reign were the conflict with the Ottoman Empire, which in the 1520s began a great advance into Central Europe, and the Protestant Reformation, which resulted in several wars of religion. Although not a military leader, Ferdinand was a capable organiser with institutional imagination, who focused on building a centralised government for Austria, Hungary, and Bohemia instead of striving for a universal monarchy. He reintroduced major innovations of his grandfather Maximilian I such as the Hofrat (court council) with a chancellery and a treasury attached to it (this time, the structure would last until the reform of Maria Theresa) and added innovations of his own such as the Raitkammer (collections office) and the Hofkriegsrat, conceived to counter the threat from the Ottoman Empire, while also successfully subduing the most radical of his rebellious Austrian subjects and turning the political class in Bohemia and Hungary into Habsburg partners. While he was able to introduce uniform models of administration, the governments of Austria, Bohemia, and Hungary remained distinct. His approach to Imperial problems, including governance, human relations and religious matters, was generally flexible, moderate and tolerant. Ferdinand's motto was : "Let justice be done, though the world perish".

Biography Ferdinand was born in 1503 in Alcalá de Henares, Castile, the second son of Philip I of Castile and Joanna of Castile. He shared the same name, birthday (10 March), culture and customs with his maternal grandfather, Ferdinand II of Aragon and became the latter's favorite grandchild; their own mothers also had the same name, Juana Enriquez and Joanna of Castile. After the death of his father in 1506, his maternal grandfather, Ferdinand II of Aragon, assumed guardianship of the prince. He was raised in the royal household and received an education in literature, the sciences, and languages. Ferdinand was a good student and grew up to be a patron of the arts and a patron of scholars at his court. The prince did not learn German until he was a young adult.

Music played an important part in his childhood. When he was an infant, his maternal grandmother, Isabella I of Castile, ordered that among the 24 servants attending the newborn, there should be four musicians. In 1505, after Isabella's death, King Ferdinand established for the younger Ferdinand a household with 62 servants and his own music chapel.Ros-Fábregas, E. (2008). "Melodies for Private Devotion at the Court of Queen Isabel". In B. Weissberger (Ed.), Queen Isabel I of Castile: Power, Patronage, Persona (p. 95). Boydell & Brewer.

In the summer of 1518, Ferdinand was sent to Flanders following his brother Charles's arrival in Castile as newly appointed King Charles I the previous autumn. Ferdinand returned in command of his brother's fleet but en route was blown off-course and spent four days in Kinsale in Ireland before reaching his destination. With the death of his grandfather, Maximilian I, and the accession of his now 19-year-old brother, Charles V, to the title of the Holy Roman Emperor in 1519, Ferdinand was entrusted with the government of the Austrian hereditary lands, roughly modern-day Austria and Slovenia. He was Archduke of Austria from 1521 to 1564. Though he supported his brother, Ferdinand also managed to strengthen his own realm. By adopting the German language and culture later in his life, he also grew close to the German territorial princes.

After the death of his brother-in-law Louis II of Hungary, Ferdinand ruled as king of Bohemia and Hungary (1526–1564).Ferdinand I, Holy Roman emperor. Columbia Encyclopedia, Sixth Edition. 2001. Ferdinand also served as his brother's deputy in the Holy Roman Empire during his brother's many absences, and in 1531 was elected King of the Romans, making him Charles's designated heir in the empire. Charles abdicated in 1556 and Ferdinand adopted the title "Emperor elect", with the ratification of the Imperial diet taking place in 1558, while the kingdoms in the Iberian peninsula, the Spanish Empire, Naples, Sicily, Milan, the Netherlands and Franche-Comté went to Philip, son of Charles.

Hungary and the Ottomans

According to the terms set at the First Congress of Vienna in 1515, Ferdinand married Anne Jagiellonica, daughter of King Vladislaus II of Hungary and Bohemia, on 22 July. The Kingdom of Hungary and Kingdom of Bohemia were both elective monarchies, where the parliaments had the sovereign right to choose the king. When his brother-in-law Louis II of Hungary and Bohemia was killed at the Battle of Mohács against the Ottoman Empire on 29 August 1526, Ferdinand immediately declared himself a candidate in the royal elections. On 24 October 1526, the Bohemian Diet, acting under the influence of chancellor Adam of Hradce, elected Ferdinand king of Bohemia under conditions of confirming traditional privileges of the estates and also moving the Habsburg court to Prague. The success was only partial, as the Diet refused to recognise Ferdinand as hereditary ruler of the kingdom.

The throne of Hungary was disputed between Ferdinand and John Zápolya, Voivode of Transylvania. They were supported by different factions of the Hungarian nobility. Ferdinand also had the support of his brother, Emperor Charles V. Nicolaus Olahus, secretary of Louis, attached himself to Ferdinand's part, but retained his position with his sister, Queen Dowager Mary of Hungary.

On 10 November 1526, in Székesfehérvár, John Zápolya was proclaimed king by a Hungarian Diet formed of the untitled lesser nobility (gentry).

On 17 December 1526, in Pozsony (Bratislava in Slovak), Ferdinand was elected King of Hungary, Dalmatia, Croatia, Slavonia, etc. by a rump Diet the higher aristocracy (the magnates or barons) and the Hungarian Catholic clergy. Accordingly, Ferdinand was crowned as King of Hungary in the Székesfehérvár Basilica on 3 November 1527.

The Croatian nobles unanimously accepted the Pozsony election of Ferdinand I, receiving him as their king in the 1527 election in Cetin, and confirming the succession to him and his heirs. In return for the throne, King Ferdinand promised to respect the historic rights, freedoms, laws, and customs of the Croats when they united with the Hungarian kingdom and to defend Croatia from Ottoman invasion.

Brendan Simms notes that Ferdinand got the Hungarian and Bohemian crowns instead of his brother, Emperor Charles V, because the Emperor was busy fighting the Ottomans in Hungary, Austria, and the Mediterranean Sea, while also fighting against France and German Protestants in Italy and Germany. Thus, the defense of central Europe was delegated to Ferdinand; he also had many responsibilities in the management of the empire. Charles V abdicated as archduke of Austria in 1522, and nine years after that, he had the German princes elect Ferdinand as King of the Romans, who thus became his designated successor.

"This had profound implications for state formation in south-eastern Europe. Ferdinand rescued Bohemia and Silesia from the Hungarian wreckage, making his north-eastern flank more secure. He told the Austrian Landtag, the assembled representatives of the nobility, at Linz in 1530, that "the Turks cannot be resisted unless the Kingdom of Hungary is in the hands of an Archduke of Austria or another German prince". After some hesitation, Croatia and the Hungarian rump joined the Habsburgs. In both cases, the link was essentially a contractual one, directly linked to Ferdinand's ability to provide protection against the Turks".

The Austrian lands were in miserable economic and financial conditions, but Ferdinand was forced to introduce the so-called Turk Tax (Türkensteuer) for the war against the Ottomans. In spite of huge Austrian sacrifices, he could not raise enough money. His annual revenues only allowed him to hire 5,000 mercenaries for two months. So Ferdinand asked for help from his brother the Emperor Charles V and borrowed from bankers like the Fugger family.

Ferdinand defeated Zápolya at the Battle of Tarcal in September 1527 and again in the Battle of Szina in March 1528. John Zápolya fled the country and applied to Sultan Suleiman the Magnificent for support.

This led to the most dangerous moment of Ferdinand's career, in 1529, when Suleiman took advantage of this Hungarian support for a massive but ultimately unsuccessful assault on Ferdinand's capital: the Siege of Vienna, which sent Ferdinand into refuge in Bohemia. A further Ottoman invasion was repelled in 1532 (see Siege of Güns). Ferdinand then made peace with the Ottomans. The Treaty of Constantinople (1533) divided Hungary between the Habsburg kingdom in the west and John Zápolya's Eastern Hungarian Kingdom, a vassal state of the Ottoman Empire.

Together with the formation of the Schmalkaldic League in 1531, this struggle with the Ottomans caused Ferdinand to grant the Nuremberg Religious Peace. As long as he hoped for a favorable response from his humiliating overtures to Suleiman, Ferdinand was not inclined to grant the peace which the Protestants demanded at the Diet of Regensburg, which met in April 1532. However, as the army of Suleiman drew nearer, he yielded. On 23 July 1532, the peace was concluded at Nuremberg, where the final deliberations took place. Those who had up to this time joined the Reformation obtained religious liberty until the meeting of a council, and in a separate compact, all proceedings in matters of religion pending before the imperial chamber court were temporarily paused."Nuremberg Religious Peace". Lutheran Cyclopedia (1899), p. 351

In 1538, in the Treaty of Nagyvárad, Ferdinand induced the childless Zápolya to name him as his successor. But in 1540, just before his death, Zápolya had a son, John Sigismund Zápolya, who was promptly elected king by the Diet. Ferdinand invaded Hungary, but the regent, Frater George Martinuzzi, Bishop of Várad, called on the Ottomans for protection. Suleiman marched into Hungary (see Siege of Buda (1541)) and not only drove Ferdinand out of central Hungary, but he also forced Ferdinand to agree to pay tribute for his lands in western Hungary.

John Sigismund Zápolya was also supported by his mother's father, Sigismund I the Old, King of Poland and Grand Duke of Lithuania. But in 1543 Sigismund I made a treaty with the Habsburgs and Poland became neutral; his son Sigismund II Augustus married Ferdinand's daughter, Archduchess Elisabeth of Austria.