Quotations
From Harry Turtledove’s Departures

After the eastern Roman Empire falls early to Islam, the Bulgars — and the Slavs under and mixed with them — turn Muslim:

Niketas answered... ‘He must choose Christ. Surely God will not allow those who worship him correctly to be penned up in one far corner of the world and bar them for ever from access to whatever folk lie north and east of Bulgaria.’

Telerikh turned to face south-east. Then the khan sank to his knees, his face turned towards Mecca. ‘La illaha illa’llah: Muhammadum rasulu’llah.’ ‘There is no God but Allah: and Muhammad is his prophet.’ ...the shahada.

Niketas caught Jalal ad-Din’s eye. More than anyone else in the chamber the two of them understood how much bigger than Bulgaria was the issue decided here today.

What eventually really happened, as commemorated by the Julian-calendar Orthodox today:

FAITHFUL, come and let us praise the God-bearing fathers Methodius and Cyril. They glistened in virtue as preachers of piety. They are true pillars and foundations of the church and celestial trumpets of the teachings of Christ. They dispelled the darkness of unbelief and, by the fire of the Spirit, burnt up dishonourable heresies. Through their translation of the scriptures the Slav people were changed from a wild to a fertile olive tree and by divine baptism were brought into the faith of Christ. Because of that they stand before the throne of almighty God, wearing their crowns. Let us cry out to them: O heavenly fathers, equal to the apostles, pray to Christ that he grant solidarity and unity of orthodoxy to all Slav peoples. Ask him to give peace to the world and to save our souls.

— Oikos from the Canon at Matins today

Да вси едино будут! (More. Disclaimer: non-Roman doesn’t necessarily mean anti-Roman.)

On war:

No glory to dying in camp of smallpox or measles or scarlet fever. No glory to typhoid either or perishing of fever after your wound went bad — and it would for we had no medicines. No glory to having your arm cut off and tossed on a pile outside a tent or under a tree while the surgeon shouted ‘Next!’ No, sir, don’t speak to me of glory.