Efendi, identified as "Eftendize" in the record of a land grant Orhan made to her as his wife, may have been Orhan's cousin, the daughter of Osman's brother Gündüz. If so, this first cousin-marriage may have function to seal Gündüz's loyalty to Osman. Kepecioğlu states, perhaps on the basis of the land record he sites, that Eftendize was the daughter of Akbaşlu Mahmud Alp, but does not posit any relation between Orhan and his wife.

In the endowment deed published by Uzunçarşılı ("Gazi Orhan Bey Vakfiyesi"), Efendi is listed as the daughter of Akbaşlu. This was the name, or probably lakab (nickname), of Orhan's uncle, and it is on the basis that Uzunçarşılı concludes that Efendi was Orhan's cousin; further possible evidence is that Suleiman's daughter Efendi, probably named after her mother, had a son named Gündüz, who was probably named after this ancestor. Uzunçarşılı is not aware that Efendi/Eftendize was Orhan's wife.

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