Köse Mihal (Ottoman Turkish: كوسه ميخال; Turkish for "Michael the Beardless"; 13th century – c. 1340)^[1] accompanied Osman I in his ascent to power as a bey and founder of the Ottoman Empire. He is considered to be the first significant Byzantine renegade and convert to Islam^[2][3] to enter Ottoman service (see Nöker).

He was also known as Gazi Mihal (Ottoman Turkish: غازى ميخال) ^[4] and Abdullah Mihal Gazi.^[5] He ruled over Harmankaya Kalesi (Ottoman Turkish: خرمن قيا قلعه سى).

Köse Mihal was the Byzantine governor of Chirmenkia (Harmankaya, today Harmanköy) and was ethnically Greek.^[6][7] According to one theory, the origin of Köse Mikhail was connected to the Cuman-Kipchaks that John III Doukas Vatatzes placed as a border force in Anatolia.^{[8][9][4][10] [11][12]} His original name was "Michael Kosses".^[7] The castle of Harmankaya was in the foothills of the Uludağ Mountains in Bilecik, Turkey.^{[4][10] [11][12]} Mihal also eventually gained control of Lefke, Mekece and Akhisar.^[13]

Even before his conversion to Islam, Mihal had an amicable relationship with the Ottoman leader, Osman Ghazi.^[14] He was an ally of Osman and his people in war, and also acted as a leader of the local Greek population. Additionally, he acted as a consultant and diplomatic agent for Osman I.^[15][16] The sources describing the reason behind Mihal's change of faith vary. One tradition emphasises the influence exerted by his friendship with Osman Ghazi, whilst another describes him having experienced a significant dream which convinced him to become a Muslim.^[17][15] His conversion is thought to have occurred between 1304 and 1313.^[18][19][20] As a Muslim, he was known as Köse Mihal 'Abd Allah (Abdullah), Abdullah being a name commonly adopted by converts.^[21]

Up to the conquest of Bursa in 1326, Köse Mihal played an important role as a diplomatic advisor and envoy of Orhan I, the son and successor of Osman Ghazi.^[22] Köse Mihal was the first important Christian renegade to become an Ottoman subject, and he played a significant role in the creation of the Ottoman state.^[23][24] Köse Mihal's descendants, known as the Mihaloğlu, were famous, particularly in the 15th and 16th centuries. They were a politically and militarily successful family of Ottoman dignitaries in Rumelia. However, they did not reach the very highest public offices.^[25]

After the taking of Bursa, Köse Mihal is no longer mentioned in the sources. Kreutel notes that Köse Mihal died around 1340.^[26] According to some historians, Köse Mihal was buried at Türbe, Edirne (Adrianople), in a mosque he himself built,^[21] in this tradition Köse Mihal was believed to have lived until after the Ottoman capture of Adrianople by Murad I in the year 1361. He would therefore have lived to a very advanced age indeed. However, Franz Babinger appears to have made a mistake. He confused Köse Mihal with Ghazi Mihal Bey, a grandson of Köse Mihal. Ghazi Mihal Bey built a now ruined Mosque complex, with an Imaret and Hamam, in Edirne, which was completed in 1422. The cemetery adjoining the complex holds the tomb of Ghazi Mihal Bey.^[27]

After his conversion, Mihal had two sons:^[28]

• Mihaloğlu Mehmed Bey. He had two sons:
  • Mihaloğlu Ghazi Mihal Bey
  • Mihaloğlu Hizir Bey. He had four sons:
    • Mihaloğlu Ali Bey. He married a Christian Wallachian noblewoman, Maria Craiovești, and had five sons, the third of them was:
      • Mehmed Beg Mihaloglu
    • Mihaloğlu Skender Pasha. He had two sons and a daughter:
      • Hürrem Pasha
      • Mustafa Pasha
      • Muhsine Hatun, who married the Grand Vizier Pargali Ibrahim Pasha and had a son:
        • Mehmed Şah Bey
    • Mihaloğlu Ghazi Bali Bey
    • Mihaloğlu Mehmed Bey
• Mihaloğlu Yahşi Bey

Mihal's descendants (the Mikhaloglu/Mikhaloglou; Greek: Μιχαλόγλου) held prominent positions through centuries of Ottoman history.^[6]

Previously the oldest surviving Ottoman artifact was Orhan's helmet. But on 5 December 2020, the Ministry of National Defense of Turkey announced that Mihal's sword was recorded as the oldest surviving Ottoman artifact, and was taken to Istanbul Military Museum.^[29]

• Renegade thesis
• Turgut Alp
• Konur Alp

• Dervish Ahmet-i 'Aşıki (called' Aşık Paşa, son): tevarihMenakıb u-i 'Al-i' Osman(Memories and times of the House of Osman). In Kreutel Richard Franz (Hrsg. / Editor):From Shepherd's Tent to Sublime Porte. Ottoman historian Vol 3, Graz 1959
• Joseph Hammer Purgstall:History of the Ottoman Empire. Bd.1, Pest 1827
• Nicolae Jorga:The history of the Ottoman Empire,according to sources presented verbatim reissue, Primus Verlag Darmstadt 1997
• John Leunclavius:Annales Svltanorvm Othmanidarvm, A Tvrcis Sva Lingva Scripti Frankfurt a. M. 1588/1596, German:Neu Chronica Türckischer nation of self-described Türcke ... Frankfurt a. M. 1590
• Majoros Ferenc u. Bernd Rill:The Ottoman Empire 1300–1922, Wiesbaden 2004
• Mihaloğlu Mehmet Paşa Nüzhet: Ahval-i Gazi Mihal. 1897 (Ottoman)
• Mehmet Neşrî:Kitab-i Cihan-Nümâ. Partially edited and translated in Journal of the German Oriental Society. 13. Volume 1859
• MİHALOĞULLARI published in the 30th volume of TDV Encyclopedia of Islam, pp. 24–25 in Istanbul (2005)