Géza Gárdonyi is my hero when it comes to historical fiction. I read this decades ago as a teen, but I think I now appreciate it even more. Especially the postscript with Gárdonyi's snarky comments on history writers describing and interpreting the famous battle of the Catalaunian plains. Who was the victor, Aetius or Attila (Atilla in the book)? Both armies withdrew after a senseless bloodbath. The Roman Empire was already on its way out, and the Huns' victories ended with Attila's death a year or two later.
The story is told by Zéta, a fictional first person narrator, originally from Constantinople, who is living with the Huns.
Attila is described as a shrewd, enigmatic, and very charismatic person who manages to unite tribes and races under himself. Most of those peoples have since been absorbed in other nations or have disappeared altogether. We get great descriptions of their appearances and customs.
I like the Hungarian title: "The invisible man", taken from an observation of the storyteller: "I am that Zéta. And I am convinced: no-one knows me ... One can only know a man's face, but he is not that face. He is behind the face. Invisible."