Historical novel set in Late Roman Britain

The book I am seeking to relocate is a Historical novel, set in Late Roman Britain when serious barbarian incursions had begun – late 4th to early 5th century AD. Alas, I have no recollection of either title or author, but strong memories of certain features of the book. Date of publication-wise, I read it in the mid 1970s and would guess from the style of writing (‘muscular’, unsentimental, fairly explicit) it to be published not earlier than the 1950s. The ‘hero’ is a young tribal Briton, fairly high up in his tribe, (which might be located in southern Wales – the Silures?) and perhaps heir to its Chieftain. He ends up in the Roman Army and I distinctly recall him befriending an Egyptian origin soldier and also killing (covertly – by removing the wounded man’s bandages aboard a ship) a Greek origin soldier who makes an unwelcome pass at him. As you may gather, the ‘hero’ is ruthless and one of the charms of the book is his shameless frankness re his actions and ambitions. He is also hostile to Christianity and orders a Priest’s hands chopped off for removing the coins over his pagan Grandmother(?)’s eyes at her funeral! The book starts with a short flash-forward to a time when there are no more Roman soldiers in Britain and the hero reflects that although his tribal cavalry on their pony mounts can be effective against the Saxon and other invaders, his young warriors ‘sit and sharpen their swords and dream of just one victory over the enemy’ (a near quote I think). There might also be the appearance of an Arthur equivalent figure.
I can’t find ‘hide nor hair’ of this excellent novel on the web and would love to read it one more time. Any help to that end would be enormously appreciated.

Hmm, most of the gritty, historical Arthuriana that I can think of is much too late for what you're looking for (Jack Whyte, Bernard Cornwell, etc.) and the ones I'm familiar with don't really match your description anyway. Maybe part of Victor Canning's series that starts with The Crimson Chalice? I only read the first one a long time ago and don't remember much. Maybe something on this list will jog your memory: https://www.librarything.com/list/9916/all/Modern-Arthurian-Fiction

This reminded me of Threshold of Fire by Hella Haasse , but not sure if all details match.

Have a look at Alfred Duggan's books. He was writing at the right time period and wrote historical novels. I have read Conscience of the King which is set in Britain at the end of the Roman Empire, but features a Roman of Saxon descent who ends up founding a Saxon Kingdom and fighting against a King Arthur character. Maybe he wrote another book from the British point of view.

Many thanks all of you, but I've checked out your kind suggestions and still no joy....

Probably another red herring, but could it be a Rosemary Sutcliff? She was writing in the fifties and sixties, and most of her books are set in late-Roman or Arthurian Britain. But I don't recognise the plot...

A Worldcat search turns up The Eagles Depart by John Gloag that sounds like a possibility. The synopsis from Goodreads says:

Set in period 337-420 A.D.
The purported autobiography of a Brittano-Roman, Marcus Geladius. His life spanned the withdrawal of the legions from Britain. This womanizer and hellraiser was the grandson of a British tribal king on one side and the grandson of the commander of a Roman legion on the other. From recruit to legion commander himself, he fought to protect his family and friends from Irish invader and Roman bureaucrat alike.

Dear indybr12 - I do believe you've got it! In which case, a thousand blessings upon you for solving a question that has been nagging away at the backburner of my brain (and eating up hours of fruitless Google searches) for decades now!
I also see that Gloag wrote two more books in a loosely connected Romano-British series, so they and 'The Eagles Depart' are on order as I type. Many thanks again for taking the time and trouble.
I don't suppose I can ask you to turn your proven abilities to my other, even longer-standing, query posted the same day (31st Oct) re '1950/60/s children's book - caves/labyrinth permitting time travel'? If so, you qualify for official 'Very Wonderful Indeed' status...

I thoroughly enjoyed this thread. John Gloag wrote a prodigious number of architecture, furniture & industrial design books...and then a few collections of short stories and his Roman stories.

>8 jawtalleyrand2323: Excellent! I'm so glad that's the right one. Happy re-reading! I'll check out your other query. Maybe my luck will hold out for a second search.

>9 SaintSunniva: Interesting info about John Gloag. That's quite a range of writing topics.