@kehribar-sultan: “I would not agree with you. I believe Fatma Sultan existed, just there are some occasions that has to be determined and investigated more. During her father's reign (cca. 1517-1518) she send a letter to him that she is for a year married to man who does not see and respect her and indirectly asked him to remove here from Teke and bring her back to his side.”
Hi! This was actually Sofu Fatma Sultan's letter to her father, Sultan Bayezid II (she had gotten misidentified in this letter featured in “Harem'den Mektuplar”)— the homosexual Mustafa Paşa in question was her second known husband— we know that Fatma Sultan binti Sultan Bayezid II was firstly married to Güzelce Hasan Paşa (for instance, check out Zehra Kandal's 2021 study titled, “II. Bayezid’in Ailesi ve Gülruh Hatun”). Anyways, I got to know about Mustafa Paşa actually having been the second husband of Fatma Sultan binti Sultan Bayezid II, with the aid of the amazing @darkblureer-sara!
The study by Mustafa Çağatay Uluçay titled, “II. Bayezit’in Kızı Fatma Sultan’ın Kocası Çapkın mıydı” demonstrated how Fatma Sultan was the most unfortunate of Sultan Bayezid II’s daughters. Uluçay had described Mustafa Paşa, the son of the Grand Vizier Davud Paşa as a debauched and immoral man—loud, lewd, and infamous for his inappropriate relations with young boys and men.
When her husband was appointed governor of Antalya, Fatma Sultan too moved there with him. However, over the course of time, his conduct exacerbated to the point that she could no longer tolerate the public scandal.
She ultimately wrote this aforementioned letter to her father, Sultan Bayezid II, revealing the shameful conduct she had been forced to endure for years, an excerpt of which delineates how desperate she was to leave her disgraceful husband and come back to her father:
“My sultan, dear father, let me wear cloth of coarse wool instead of the cloth of rudeness, let me eat barley bread, just let me live in your shadow!”
Furthermore, Eda Öner's study, “Maktûl Kara Ahmed Paşa'nın Siyasi ve Idari Kariyeri” also illustrated with contemporary Ottoman court records that the Fatma Sultan married to him wasn't a daughter of Sultan Selim I, but the daughter of a certain Mustafa Bey (hence, this Fatma Sultan was a grand-daughter of Sultan Bayezid II via one of his daughters who had her with a certain Mustafa Bey):
“Indeed, it is known that Kara Ahmed Ağa married Fatma Sultan. However, the widely held belief in the literature that Fatma Sultan was the daughter of Selim I and the sister of Sultan Suleiman is incorrect. For in two Sharia court records written after Kara Ahmed Ağa's execution, which show that he freed four of his slaves during his lifetime, his wife is referred to as 'Fatma Sultan bt. Mustafa Bey'. Based on this, it can be understood that Fatma Sultan's father was not a member of the dynasty, but she belonged to the dynasty through her mother.” —Pg 16 (translated from Turkish)
An Istanbul şeriye sicilleri (Legal registers) document, dating after the execution of Kara Ahmed Paşa (which happened on September 29, 1555, two days after his deposition from Grand Vizieriate as per Court Chronicler Koca Nişanci Celalzade Mustafa Çelebi) mentioned that "Fatma Sultan bint Mustafa Bey" filed a petition to manumit several of the deceased Paşa’s servants, identifying herself explicitly as his wife.
Besides, Hüseyin Ağa bin Abdurrahman (the brother of the late Grand Vizier Ahmed Paşa) and Fatma Sultan bint Mustafa Bey (the wife of the late Grand Vizier Ahmed Pasha) — are identified in one of the two court documents as the legal heirs and authorized administrators of the estate and properties of the deceased Grand Vizier Ahmed Pasha. — Numarali Sicil (H. 964-965 / M. 1557-1558)
Essentially, there's no credible historical basis for the existence of any Fatma Sultan binti Sultan Selim I.
Even prior to coming across this study (which was again recommended to me by @darkblureer-sara), I had my doubts because contemporary European accounts never mentioned Kara Ahmed Paşa as Brother-in-law, even when they clearly mentioned Lütfi Paşa and earlier Ferhad Paşa and Çoban Mustafa Paşa (see: Venetian ambassador, Pietro Bragadin's June 1526 report) as Brothers-in-lae as well! Additionally, even Safavid accounts don't mention Kara Ahmed Paşa or Makbul-Maktul İbrahim Paşa as Brothers-in-law either (which @mehrab-k kindly brought to my attention!)
Also, Sultan Selim I appears to have married only one daughter, Şahzâde Sultan (first of the two daughters born of Ayşe Hafsa) to the erstwhile Bostancibaşi, then Admiral Iskender Paşa off in 1509. She's consistently referred in some Archival orders and correspondence between Sultan Bayezid II and Sultan Selim I simply as “Hanım Sultan” (which means: “Madam Princess”— very standard manner of referring to an Ottoman Princess, and in fact, Mihrümah Sultan would be referred to by others and even sign herself off as “Hanım Sultan” too!)
We of course know that Gevherhan wasn't Sultan Selim I's daughter either. Sofu Fatma Sultan's son, Mehmed hadn't married any daughter of Yavuz Sultan Selim in 1509 as had been believed in popular historiography. The July 2025 academic dissertation titled, “İlme ve Eğlenceye düşkün bir Şehzâde'nin Hayati: II. Bayezid'in oğlu Alemşah” by Hamit Şafakcı meticulously proved via archival documents/registers that the aforementioned marriage was contracted with Hanzade Sultan binti Şehzâde Alemşah.
Also, while I've been researching more about it, evidently Selim held off marrying the rest of his two other daughters who survived to adulthood owing to still somewhat volatility of politics and well, the “betrayal” by his Damad Iskender Paşa, Şehzâde's husband who was executed by him in 1515 consequently.
[These two other daughters besides Şahzâde Sultan who made it to adulthood were Beyhan Sultan (the second of Ayşe Hafsa's daughters besides Şahzâde Sultan) and Şahihuban Sultan (born of an unknown concubine).]
This was the case until 1517 when Selim I remarried his daughter, Şahzâde Sultan to Çoban Mustafa Paşa (note that Şehzâde's first husband Iskender Paşa had been executed in 1515) and most probably, Beyhan Sultan (she had been unmarried as of the September-October 1513 register which I'd discussed and elaborated about here last month) must've been firstly married off at this time too, but I'm yet to find out to whom (I've found yet another overlooked report that mentioned that Selim had decided all of a sudden to marry off his daughters circa 1517— I'll state these reports properly some other time as I can't locate them presently).
Beyhan Sultan would be married off—for the second time (most probably) by her brother in February, 1522 to Ferhad Paşa (and well, he would execute him on November 1, 1524 in Edirne owing to treason and him drawing a weapon in the Divan in front of Süleyman!)
Şahihuban Sultan appears to have been born much later (c. 1505?), and it seems her marriage to Lütfi Paşa was her first marriage effected by her half-brother, Süleyman by March 10, 1523 (22 Rabi-ul-ahir, 929)— possibly she was married simultaneous to Süleyman's full-sister, Beyhan Sultan.
Conclusion: Anyways, from my extensive research thus far on Yavuz Sultan Selim's family from both Ottoman and European primary sources, I've concluded that only 3 of Yavuz Sultan Selim's daughters had survived to adulthood: Şahzâde Sultan, Beyhan Sultan and Şahihuban Sultan.
The first two were born of Vâlide Sultan Ayşe Hafsa Hatun— yes, actually Ayşe Hafsa never received the title of “Sultan” as is popularly believed, about which I've talked here— and the latter was born of an unknown concubine who was alive as of November 1556. Selim also had at least one other daughter, Kamer or Kamerşah. who died in childhood in 1503.
It was nice to be affirmed in this conclusion by Professor Feridun Emecen's research which also concurred that only these 3 aforestated (adult) daughters of Yavuz Sultan Selim actually figure into contemporary Ottoman documents. Thus, from all of this, Sultan Selim I didn't have any daughters named Hatice and Fatma— their existence has been essentially contrived over the centuries by compounding and accumulation of historiographical errors. For more information about İbrahim's wife and the so-called Hatice Sultan myth, read this post.