Aburni was a king of Nobatia, who ruled around 450 AD as the successor of Silko.
The letter was written in bad Greek directed by the king of the Blemmyes, Phonen, and his son, the phylarch Breytek, to Aburni Nakase and his sons, and Mouses.
In the letter, Phonen makes it clear that he is an enemy of the Nobadians and mentions various conflicts that he had with Silko and his successor Aburni.
Phonen reports that animals were exchanged for land, whereupon Silko killed the Blemmyrian phylarch Yeny and kidnapped numerous priests.
However, Phonen is the last recorded ruler of the Blemmyrians and one may assume that Aburni managed to destroy them and take over their empire.