II. Murad part 2

War with Venice and conquest of Thessalonica 

Main articles: Ottoman–Byzantine War (1421–1424) and Ottoman–Venetian War of 1423–1430
After the Battle of Varna II. Murad and the beheaded Polish-Hungarian King Ladislas
During the siege of Constantinople, the Venetians initiated negotiations with Byzantium to take Thessaloniki and the Peloponnese under their control. In 1423, while the Ottoman army was besieging Thessaloniki, they made an agreement with the Byzantines to hand over Thessaloniki to the Republic of Venice, and Venice took possession of Thessaloniki. In 1424 the Venetians blockaded the Dardanelles.

Thereupon, with the concern that Constantinople might be left to the Venetians, II. Murad made an agreement with Byzantium through the Genoese in 1424. According to this treaty, the Byzantine emperor agreed to pay 30 thousand ducats of gold as tax every year and to return the lands on the Aegean and Black Sea coasts , which had been taken over by the Byzantines after the Battle of Ankara, to the Ottomans.
 
In the same year, raiders under the command of Evrenosoğlu İshak Bey launched a series of attacks against Albania and local Albanian lords. Albanian lords named Yuvan Kastrioti and Atariti only came to power during World War II. They were able to accept Murat's superior sovereignty and prevent these raids. Kastrioti had to send his 4 sons to the Ottoman palace in Edirne to receive hostage and education. Skanderbeg , the youngest of these children, later caused great trouble to the Ottoman state. 

In 1424, in the Edirne palace, with a big wedding ceremony, II. Murad married Tacunnisa Hatice Halime Hatun, the granddaughter of Candaroğulları Bey İsfendiyar Bey . At the same ceremony, II. Murad's sisters were also married off. Sultan Hatun with İsfendiyaroğlu Kasım Bey; Ayşe Hatun married Karaca Bey, one of the Ottoman commanders, and Hafsa Hatun married Mahmud Bey, the son of Çandarlı Halil Pasha . 

War again in Anatolia and Rumelia 

 Annexation of the Aydınoğulları Principality (1425–1426)
II. In 1425, Murad attempted to achieve unity in Anatolia . First, they dealt with İzmiroğlu Cüneyd Bey, who was given the Aydınoğlu Principality in the Düzmece Mustafa case . Cüneyd Bey supported the real and fake prince revolts one after another. First, he helped Prince Ismail in his rebellion, and in 1425 he supported a new, unknown Düzmece Mustafa, who rebelled in Thessaloniki with Venetian support. II. Murat gave back the port colonies in the Black Sea to the Genoese and made an agreement with them, preventing Cüneyt Bey from providing support from the sea by using the Genoese fleets brought from Lesbos and Chios. Then, after a long struggle with a land army with the aim of exterminating the Izmiroğulları, Cüneyd Bey, his family and other members of his dynasty were captured in 1426 and all were executed. 

In 1426, II. Murad sent armies from several branches in Rumelia and started a military operation in Rumelia and the Balkans. One target of this operation was the rebellion started by a new "Duzmece Mustafa" of unknown origin, who was supported by Venice, in Thessaloniki and its surroundings. The other target was the unrest in the Balkans with the support of the Hungarians. II. Murad personally went from Sofia to Vidin at the head of an army. Ottoman raiders attacked and plundered Bosnia and advanced as far as Croatia . 
Then Menteşe and Teke principalities joined the Ottoman lands. However, the sovereignty of the Karaman and Çandarlı principalities further east was not ended. One reason for this was that this policy threatened that Shah Ruh , who succeeded Timur, would declare rights over all the lands that were once under the rule of the Seljuks and Ilkhanids and launch an invasion movement.

In 1428-1429, a plague epidemic began in the Ottoman country. During this plague epidemic, Emir Sultan, a well-known thinker in the world of Islam and Sufism in Bursa ; statesman, soldier, architect Hacı İvaz Pasha ; Grand Vizier Çandarlı İbrahim Pasha and II. Murad's younger brothers, Mahmud Çelebi and Yusuf Çelebi, who were blindfolded, lost their lives. 
In 1429, Germiyanoğlu II, who had no sons . Following the death of Yakup Bey , the Germiyanoğulları Principality joined the Ottoman lands upon his will .

II. After Murad established peace in Anatolia and the plague epidemic was overcome, he directed all his power against the Venetians. Until this time, the Republic of Venice had been blockading the Dardanelles, holding Thessaloniki. The Ottomans captured Thessaloniki on 29 March 1430, then "Yuvan-ili" and then Ioannina . An Ottoman-Venetian Treaty was signed. 

Land census began in Rumelia in 1430. After these censuses, the timar system was implemented on these lands. After the Ottomans captured Thessaloniki , Evrenosoğlu İshak Bey, the governor of Skopje, attacked the lands held by the local rebel Albanian lord Yuvan Kastrioti, captured his fortified positions and destroyed all but two of them. Albanians, who were always local rebels, started the Albanian rebellion, which continued in the period 1432-1434, against the implementation of the timar system. The Albanian lord Gjergj Ariani, who was in Edirne, escaped from here and took over the management of this rebellion. In the winter of 1432-33, which was the beginning of this rebellion, II. Murad spent the winter in Serres and a raiding army under the command of Evrenosoğlu Ali Bey was sent against the Albanian rebels. During this winter, the Albanians ambushed this raider army in Shkumbin, a narrow valley, and the raiders suffered great casualties.  In 1433, Albanians again successfully resisted the raid of Evrenosoğlu Ali Bey. In 1434, the Albanians gained some success against Ottoman raiders through gang and ambush warfare. However, in 1435 and 1436 Evrenosoğlu Ali Bey and the other raider lord Turahan Bey managed to suppress the Albanian rebellion.

Annexation of Serbia 

Sultan II. Painting of Murad by John Young
During the Ottoman civil war, Hungarian influence in the Balkans increased, and after the death of Serbian Despot Stefan Lazarevic in 1427, a conflict broke out between Hungary and the Ottomans over the Serbian throne.

In 1428, Güvercinlik castle , located on the Danube River in the northeastern part of Serbia, was captured by the Ottomans.

As a result of a 3-year agreement between the Hungarians and the Ottomans in 1428, George Brankovic was recognized as the Serbian Despot. This 3-year agreement was renewed once again.

On the other hand, II. While Murad was busy working in Rumelia, he recaptured the old Hamidoğulları lands in the Karamanoğulları Lakes Region in Anatolia and II. Murad had to stand by and watch this.

When the renewed treaty expired, in 1434, Hungarian King Sigismund II. He sent an envoy to Murad and formally requested the recognition of Hungary's supreme sovereignty over Bosnia , Serbia and Bulgaria . With this move, Hungary declared war. Those who were against the Ottoman Empire began to gather around the King of Hungary. Among them, Bosnian King II. Tvrtko , daughter of Mara during World War II. There were Serbian Despot Yorgo Brankovic , who was married to Murad , Vlad Drakul I, who captured the principality of Wallachia with the support of Sigismund, Prince Davut , son of Sözcü Bey , many Balkan nobles seeking the right to the throne, and many noble lords. However, this very complex alliance search process developed very slowly and no aggressive merger development emerged. On the other hand, in the face of the increasing influence of the Hungarians, II. Starting from 1434, Murad began to follow a more aggressive attitude in the Balkans.
However, important developments in Anatolia and Asia, namely the possibility of Timur's grandson Shahruh, the Timurid Gürkan ruler, turning to Anatolia and the Karamanoğulları taking back the old Hamideli lands with an aggressive attack, II. He prevented Murat from drawing his attention to the Balkan problems. Shah Ruh, the Timurid Gurkan ruler, supported the Karakoyunlu ruler Skanderbeg. İskender Bey defeated the Akkoyunlu ruler Karayülük Osman and captured the entire Eastern Anatolia. In 1434, the Timurid Gürkan ruler Shah Ruh organized a remedial operation against the Karakoyunlu State. In 1435-36, he attacked Skanderbeg and dethroned him from the Karakoyunlu throne. He replaced Cihan Shah, who was loyal to him, on the Karakoyunlu throne and appointed him governor of Tabriz. Iskender Khan also took refuge in the Ottoman Empire and stayed in Tokat in the winter of 1435-36. Here are the developments in the east II. It made Murad and the Ottomans very suspicious. But in 1436, the Timurid Gurkan ruler Shah Rukh returned to Khorasan, and the possibility of an expedition to Anatolia became much less likely.
Taking advantage of this, II. Murad went on an Anatolian expedition in 1437 and brought the lands of Konya, Beyşehir and Hamideli, which had been taken over by the Karamanoğulları, back under the Ottoman administration. 

After the death of the Hungarian King Sigismund on December 9, 1437, without leaving a male heir, the dynastic problems that would come to power in Hungary created quite a turmoil in Hungary. The front that Sigismund tried to establish against the Ottomans also disintegrated. Finally, the Hungarian nobles defeated Henry III of the Jagiellonian Dynasty, King of Poland since 1434. They elected Vladislav as King of Hungary and he was given the name Vladislav I for the Kingdom of Hungary.

II. Murad made good use of this opportunity and stayed in Rumelia for 3 years, focusing especially on the problems of Serbia and Wallachia. He ensured that the principalities of Serbia and Wallachia were unconditionally attached to him. Then in 1438, II. Murad went on his first Hungarian Expedition. He crossed the Danube , attacked and destroyed the castles of Severin, Demirkapı , Orsova and Sebeş and besieged the castle of Zeybin (later Hermannstadt and now Sibiu ), the center of Transylvania . After capturing this castle, crossing the passes of the Carpathian Mountains and entering the lands of Wallachia, he returned to Edirne via the Earth . This was the first large-scale campaign of an Ottoman sultan.
 
In 1438, II. Murat turned towards Serbia. He invaded the Serbian Despotate by conquering the new important defensive fortress and capital of Smederevo , which was allowed to be built by Brankovic . He put an end to this state and declared Serbia an Ottoman province . The raiders under the command of Skopje Sanjak Bey Evrenosoğlu İshak Bey advanced as far as Yayçe, the capital of the Bosnian Kingdom. At that time, Bosnian King II. Tvrtko's death resulted in the Bosnian Kingdom being shared between two heirs and Herzegovina in the south gaining a separate independent administration. II. Murad took advantage of this and made all three administrations pay tribute.
The Hungarians appointed the new King of Hungary as King III of Poland at the time . They chose Wladislaw as the Hungarian King Wladislaw I, and the kingdoms of Poland and Hungary came under the rule of the same person. Wladislaw I appointed a person named János Hunyadi to the voivodeship of Erdel , whose family origins are very mysterious, but he claimed to be a Wallachian nobleman. The Ottomans and Ottoman historians also refer to this person as "Hunyadi Yanos". Thus, János Hunyadi, a person who fought against the Ottomans with a Crusader spirit for 20 years, was considered a national hero by the Hungarians, and eventually came to the Kingdom of Hungary with his son Matyas, entered the Balkans political scene. In 1441 János Hunyadi recaptured Samothrace from the Ottomans and won several victories against Ottoman troops sent to Transylvania.

Historians do not have any documents about the details of the ceremony and the information that could reveal the reasons why this renunciation and transfer ceremony was held in Mihaliç, where the dynasty farm was located, and not in the state capitals Edirne or Bursa. Meanwhile, it is not clearly known why such a heavy state burden was given to a child between the ages of 12 and 15 (due to an uncertain date of birth). Historians have put forward various reasons for Mehmet II to be brought to the throne. The most important of these is the intrigues of Çandarlı Halil Pasha , who was the Grand Vizier . Another reason is the power conflicts between the viziers (especially between the grand vizier and the viziers who were the lieutenants of Mehmet the Conqueror). The other reason is that Murad II was under the auspices of the Byzantine Emperor in Constantinople . It has been claimed that he wanted to strengthen his son's entrenchment on the throne against Orhan Çelebi, who was the ruler and claimed the Ottoman throne. 
His son and conqueror of Istanbul II. mehmed

While the Hungarians and their allies landed in Izladi, the Italian-born Pope IV in Rome. Eugene was eager to prepare a new Crusade. Byzantine Emperor VIII, who came to Europe and Italy from Constantinople in 1437. John 's participation in the Council of Florence and the acceptance of reconciliation between the Christian Orthodox and Christian Catholic sects and the establishment of unity under the Papacy, albeit for a short time; The acceptance and declaration of a union document called "Laetentor Corele" in the Council for this union played an additional role in the Pope's enthusiasm for this Crusade. Pope IV Eugene began to see himself as a champion who united Christianity, expelled the Ottomans from the Balkans and brought mono-denominational Catholic Christianity back to this region. He also saw Vladislav I, the king of Poland and Hungary, who provided the majority of Christian soldiers for this campaign, and his famous general, János Hunyadi, who was the Voivode of Transylvania at the time, as the commanders for this new Crusade. The pope sent Cardinal Gialiano Cesarini, the pope's closest political advisor and who had played a leading role in the Council of Florence, as the pope's representative before the Polish/Hungarian king. Cardinal Cesarini was completely against the "Treaty of Edirne-Segedin". He told the young Polish/Hungarian king that a treaty made with a non-Christian would be deemed invalid according to Christian principles; Contrary to the oath given by a non-Christian on the holy book will not be considered a sin by Catholic Christians, and if the king does not keep this oath and thinks that he has committed a sin, the pope, who is the highest Catholic priest, will act as a confessor and make sure that the king is religiously forgiven even while he is alive. He convinced Vladislav by constant suggestion. II. Murad's unexpected abdication also had a major adverse effect on the Hungarian king, who had already signed the Treaty of Segedin with great difficulty and against all the advice of his advisors. II. Murat abdicated and was succeeded by his son, II. With Mehmed's accession to the Ottoman throne, the claim that the Treaty of Edirne-Segedin was invalid gained more strength. Because the ruler who signed this agreement and personally swore the oath (Murad II) was no longer on the throne. The new sultan who ascended the throne was not a party to the treaty. Thus, this agreement and oath were invalid. The Hungarian king Ladislas declared that the oath he had given to continue this treaty was not against the new sultan and published this as an excuse for the invalidity of the treaty. Thus, with the suggestions of the papal representative and flimsy excuses, the Hungarian king Vladislav announced to all Christian parties that the Edirne-Segedin Treaty he made with the Ottomans in August was invalid and that he would go on a new Crusade the following year. 

II. Murad Khan