I would support the recommendation of "The Duellists". It is one of my all-time favorite movies.
A couple of Roman movies that do their work well, for the time in which they were made, are "Spartacus" and "The Fall of the Roman Empire". The gladiatorial training scenes in "Spartacus" are better than in "Gladiator", but the fight scenes lose. But how can one not be stirred when Crassus' legions come up over the hill and open up into battle order? Great stuff, even if they don't use thrown pila properly! "The Fall of the Roman Empire" stars Sophia Loren, so that would be enough to recommend it, but it has some very interesting bits. Stephen Boyd is shown wearing a Hedderenheim helmet, a type only just discovered at that time, and the battle scenes in the German forests are quite good, as are the battle scenes in the mid-east deserts. There is a very silly chariot race through the German woods and the Boyd, as Lucius Verus, duelling Commodus at the climax with pila, the heavy javelins of the Roman legions, a particularly silly bit, but the movie is very good other than those two things.
I loved the 1990s "Three Musketeers" with Keefer Sutherland and Charlie Sheen. Lots of swashbuckle and slapstick as well as good sword action. In that vein, but more sophisticated, is "Princess Bride", an absolute classic. The swordplay is unrealistic, but the verbal byplay is a stitch.
Errol Flynn's "Robin Hood" is great swashbuckle, and Basil Rathbone, the fellow who played the Sheriff of Nottingham, was a world-class fencer who would get disgusted with Flynn's antics with a sword. I had the misfortune to see Costner's "Robin Hood; Prince of Thieves" on the same day that Flynn's movie was on the TCM channel. Costner lost in comparison. But then Mel Brooks came out with his "Robin Hood; Men in Tights". It is typical Mel Brooks borscht belt humor, but funny as H*ll, and stars Cary Elwes, the Dread Pirate Roberts of "Princess Bride".
Two other recommendations and then I'll let you go. I loved the recent take on Zorro with Antonio Banderas and Anthony Hopkins. It is a great movie made even tastier by Carolyn Zeta-Jones. And to make a nice pair, get the old George Hamilton IV spoof, "Zorro the Gay Blade". I won't even try to describe it except to say that it probably couldn't be made today and that it is still funny as all H*ll, and that from strong supporter of gay rights.
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Walk in the Light,
Hugh Fuller