To add to the other post on the subject, not only did Mehmed the Conqueror call himself the Caesar of Rome, he frankly had a better claim than some undisputed roman Emperors to the title. The second Sultan of the Ottoman Beylik, Orhan, had the daughter of Emperor John VI Kantakouzenos, Theodora Kantakouzene, as his fifth wife, so there was some blood-derived legitimacy. Not to mention that Gennadius Scholarius, Ecumenical Patriarch of Constantinople, also backed up the claim. Granted, he was installed in that position by Mehmed the Conqueror, but that's nothing new for Roman Emperors.
Mehmed even wanted to try and conquer Rome itself, and he had actually started an Italian campaign before he died in 1481. His successors didn't share that interest but they did briefly make the Austrians stop making any mention of the HRE in the 1533 Treaty of Constantinople. A desire to de-legitimize the competing claim was probably also part of the motivation of the repeated failed attempts to capture Vienna, too.
To add to the other post on the subject, not only did Mehmed the Conqueror call himself the Caesar of Rome, he frankly had a better claim than some undisputed roman Emperors to the title. The second Sultan of the Ottoman Beylik, Orhan, had the daughter of Emperor John VI Kantakouzenos, Theodora Kantakouzene, as his fifth wife, so there was some blood-derived legitimacy. Not to mention that Gennadius Scholarius, Ecumenical Patriarch of Constantinople, also backed up the claim. Granted, he was installed in that position by Mehmed the Conqueror, but that's nothing new for Roman Emperors.
Mehmed even wanted to try and conquer Rome itself, and he had actually started an Italian campaign before he died in 1481. His successors didn't share that interest but they did briefly make the Austrians stop making any mention of the HRE in the 1533 Treaty of Constantinople. A desire to de-legitimize the competing claim was probably also part of the motivation of the repeated failed attempts to capture Vienna, too.