King Habsburg Ferdinand I of Hungary

Habsburg Ferdinand, King of Czechia and Hungary; his story cannot be separated from King Szapolyai`s. Now, let me talk about Ferdinand`s deeds only until 1541. 
His slogan was: “Let the Truth rule the world or let the world perish.”
Habsburg Ferdinand (1503-1564) became related to the Hungarian kings from the ancient Árpád dynasty through his marriage with Princess Anna, in 1521 and he was the one who gained the biggest profit from the death of King Louis II of Hungary. (Not to mention his elder brother Emperor Charles V who could give the rich Hungarian silver and copper mines back to his debtors, the Fuggers.)
Ferdinand had come from Spain and it took him some time to learn German and when he married the Hungarian Princess Anna, he had to struggle with the Hungarian language as well. Two things played a major role in his character that I found interesting: on one hand, he could not handle well the power-hungry East-European aristocrats of Hungary because of his upbringing in the Spanish court where he had got used to the idea of absolute power. Secondly, he had helped his elder brother Charles all the time despite the fact that Charles was quite jealous of him. 
As for his character, Ferdinand was not a warlike figure and didn`t like leading his troops in person, and he didn`t take delight in violence. He preferred sending his assassins against his enemies: he tried to get rid of Szapolyai when he fled to Poland but Szapolyai wrestled and killed his attacker.
He had all the motives to get rid of King Louis II and have control over Hungary and admittedly, his claims were strong. There was the Habsburg-Jagellion mutual succession treaty that he could refer to. First, he got the Czech crown, then he was crowned as king of Hungary in 1527 and he began fighting against King Szapolyai who had been elected before him. The Dual Kingship tore the country into two.
Most of the Hungarian lords were on Szapolyai`s side, though and as I had written before, the Jagellion treaty was voted down by the Hungarian Estates who elected King Szapolyai, claiming that only a native Hungarian can be the king of Hungary.
The country became a battlefield between them and Ferdinand succeeded to chase Szapolyai to Poland. In the hope of finding a protector against the Ottoman Empire, the Hungarian nobility began to support Habsburg Ferdinand, thinking that he would be the stronger.
At this point, Suleiman entered the theatre by declaring war on Austria and Hungary under the excuse of helping Szapolyai back to his throne. Although he had only two weeks for the siege of Vienna in the autumn of 1529 and it proved to be his first failure abroad, he tried again in 1532 and was delayed only by the heroic defenders of a small Hungarian Frontier castle called Kőszeg. We will talk much about these events later.
On top of that, the Habsburgs had instigated the Serbians of southern Hungary against the Hungarians and massacres and uprisings were destroying the country from 1526 on. 
Before long, many Hungarian nobles got disappointed in the Austrians’ help and sided with the national king, János Szapolyai. 
Finally, the two kings made a treaty in Nagyvárad (Oradea), 1538, and divided Hungary between them. Szapolyai agreed in it to cede his lands to Ferdinand in case he died without an heir. 
To everybody’s surprise, King János Szapolyai had a male child in 1540, who became our last elected national king and the first Prince of Transylvania at the same time: János (John) Zsigmond II. 
The baby boy was crowned the same year of his birth because of his father, King János Szapolyai, died in 1540. 
The little boy remained in the palace of Buda with his mother, Queen Isabella Jagiellon, the eldest daughter of the Polish king. 
The young Queen, listening to the advice of his Jesuit priest called Brother György, handed over the castle of Buda to the Turks in 1541.
Before judging too harshly over the widow and blaming the departed king, it is very important to look into the matter, regarding the relationship of King Szapolyai and Sultan Suleiman. Szapolyai naturally wanted to keep the power for himself and for his son. We have to add that King Ferdinand was also willing to pay even higher annual taxes to Suleiman in exchange for his safe rule over the East Hungarian lands.
He seemed to have been more worried from the Habsburgs than from the Turks, besides, he simply had no choice left. 
We must admit that yes, King János Szapolyai had allied himself with Suleiman the Magnificent in 1528. 
We mustn’t forget at the same time that before the alliance, he had been pleading for help against the Austrian usurper from all the Christian rulers, sending envoys to the Pope, to the French and Polish kings and to Bavaria and many more places. 
Yes, King Szapolyai was humiliated by the Sultan himself when in 1529 Suleiman had gone against Vienna and King Szapolyai was made to kiss his hand, no other place than at the battlefield of Mohács.
In return, the Sultan gave him back the Holy Crown and restored him to power. 
The Sultan sent an Italian adventurer called Lodovico Gritti to act as a Governor over King Szapolyai on his behalf. The King could get rid of him only in 1534 when Gritti was not favored anymore by the Sultan.
We must remark, that King Szapolyai never sent soldiers to support the Sultan against the Habsburgs. After King Szapolyai’s death, the Habsburgs sent a strong army to take the castle of Buda in 1541. Their formidable army was led by Willheim von Roggerdorf and they laid siege on Buda which was heroically defended for three months before Sultan Suleiman arrived and defeated the Austrian usurper’s army. 
Having scattered the Habsburgs, Suleiman just walked into Buda and the Turks remained there for 150 years.
So I think if the Habsburgs hadn’t interfered into Hungary’s affairs, the Turks would have had a lot more difficulties in occupying the country. Hungarian historians are very divided on this question.
After defeating the Austrians at Buda, Suleiman ceremonially watched the execution of 600 German and 600 Czech prisoners and then finally let Queen Isabella and her son go and „gifted” them the control over the territories over the Tisza river and Transylvania, in exchange for an annual tax. 
In the first picture, you can see how Ferdinand entered Hungary in 1527.