DD read it (12) last week and could read it fine but kept getting distracted because it wasn't enthralling at all. As she wrote in her school book report. So probably 12 youngest. I read it at that age too. At school same as her.
I think I was probably still at Primary school but I was a voracious reader. I know how old I was when I started on Mary Renault's books - they were in the library at secondary school. I think I had read Eagle by the time I started on those.
Oh, thank you. DS is nearly 9, sounds like perhaps we need to wait a couple of years. He's a good reader but especially if it is a bit heavy going, I think we will try Rotten Romans or something instead to get him interested in the topic.
There is a really good book called The Woolpack by Cynthia Harnett. It's set in the medieval period and is a really easy read for that age group. Might be a 'way in' to historical fiction. Description here
I think that all these "old" children's books work better as read aloud for modern children. I read The Eagle of the Ninth to ours when they were, I think, 6 and 10 and they loved it. But I don't think they would have wanted to read it for themselves even when they were older. Tastes, vocabularies and prose style changes.