That's a reference to emperor-in-exile Julius Nepos, who had been driven out of Italy in 475 to Dalmatia (the modern Croatian coastline) and spent 475 to his death in 480 asking Zeno and Constantinople to support his claims to the throne, but no one was interested in doing so.

Some Nepos partisans even now would claim that we should date the end of the Western Empire to Nepos' death in 480, but 476 is traditional by this point.