For a Roman general to qualify for an honorary procession through Rome, the rule of thumb was that he kill 5,000 people in campaign, a number that appears paltry when set aside the military murders of the 20th century.

There is some excellent radio on television these days. I'm thinking specifically of the two history series now running at the weekend - Channel 4's three-part account of The Crimean War and, just started, BBC2's I, Caesar, a six-part account of the rise and fall of the Roman Empire. Both series could be listened to with your eyes shut and - barring the occasional moment when the voiceover refers to "these watercolours" or uses a computer- generated map - you wouldn't be at any great disadvantage to a sighted viewer. Both programmes employ distinguished actors to revivify the documentary record (I, Caesar even uses that long-time ornament of the Radio Rep company, Garard Green) and both seem to have had resort to the same sound effects record to back up the shots of triumphal friezes or watercolours. When it comes to Confused Shouts of Battle or Alarmed Whinnying it seems there's not much to distinguish Julius Caesar's Gallic wars from the Battle of Inkerman. This isn't quite fair, I know - really just a way of saying that these are unabashedly didactic programmes with little time for purely visual excursions. And you'll undoubtedly enjoy yourself more if you keep your eyes open.

I, Caesar slightly has the edge as a piece of film-making - its first episode, for example, included a lovely montage in which you saw a variety of Roman pillars backed by very different landscapes - a suggestive visual argument for the consistency with which the Imperial style was applied to different dominions. But the pictures in The Crimean War aren't merely decorative additions, either. What's impressive there is not so much the grisly watercolours of the aftermath of battle, nor even the early photographs of stoical whiskered amputees, but the eerie shots of that fabled landscape today - quite unmarked by a slaughter so intense that it left the grass "sloppy with blood". On more than one occasion the director has been able to fade from a contemporary picture of Balaclava harbour, bristling with masts, to the same hills and shoreline today, bleak and undeveloped, and it doesn't take much effort to repopulate the place with freezing, neglected soldiers.

I, Caesar began with an epigraph from Cicero - "To know nothing of what happened before you were born is to remain forever a child" - but there is a sense in which both programmes give us a child's history of the events they describe. I don't mean by this that they are sanitised, but that they are unequivocal - history here is a stuff of massy solidity rather than disputed theory. You get plenty of facts, but then those facts stay with you. Consider, in particular, the changing arithmetic of human slaughter; for a Roman general to qualify for a triumph - that is an honorary procession through Rome - the rough rule of thumb demanded that he kill 5,000 people in campaign, a number that appears paltry when set aside the military murders of the 20th century. Similarly, the death toll in the Charge of the Light Brigade was just 110 men killed, a notion of "disaster" that would soon be horribly outdated. In their day, these figures represented extremities of savagery - from our rather bloodier perspective they could almost look innocent.

Phillipa Lowthorpe's Eight Hours From Paris (BBC2) was a strange affair - a fiction that borrowed the manners of documentary in knitting together various scenes of provincial life in a Midlands town. Did these little vignettes add up to a drama? Not if you include some sense of resolution and focus in your definition, they didn't. But they did demonstrate Lowthorpe's ability to generate a subtle, poignant comedy from banal details.

Some of the scenes had the distinctive awkwardness you get when real people are asked to act out their own lives but other passages were strikingly authentic and unforced. It was full of promising inventions, rough experiments and an omnivorous observation, but in the end it felt more like an artist's notebook than a finished work

I did mean to review Food for Ravens (BBC2) today, Tony Griffiths' play about Nye Bevan, but, whether by design or misadventure, neither of the tapes dispatched arrived in time for my deadline. I will return to it tomorrow.