3 occurrences across the corpus

Kebra Nagast

Kebra Nagast 38:6

Now Baltasor, the King of Rom, wisheth that I would give my son to his daughter, and to make him with his daughter king over the whole country of Rom.

Kebra Nagast 72:9

And Zanbares died before [this] and Baltasor, who was of his kinsmen, became king.

Kebra Nagast 72:29

And Solomon the King wrote and sent a letter, saying, "Peace be to Baltasor, the King of Rome!