The Last Legion

There's a movie poster available for the upcoming film adaptation of Valerio Massimo Manfredi's novel L'ultimo legione (the Last Legion):The story offers a novel (no pun intended) sequel to the mysterious fate of Romulus Augustus (often called the last emperor of the Western Roman Empire) as well as a clever origin for the Arthur legend. Romulus, who would have been about 12-13 when Odoacer forced his abdication, was lost to history. Here, he finds a sword that once belonged to Caesar and escapes to Britannia in search of the last loyal legion.

A serious question: Were there any legions to speak of in 476, and if so were there any legions in Britannia? My guess is no on both counts.

I'll be interested to see how accurately the movie plays out, taking into consideration the necessary fabrications. How consistent will it be with the world that it rewrites?