"This is Claude," she says. "Claude is your special helper, and he's going to be very good today."
Claude and I have just got the hall ready when the remainder of Year 4 comes bowling in. I present the problem. The Roman Emperor needs a triumph and our job is to find him a land to conquer and then plan an invasion. I present the options: Africa, Germania or Britannia. Please God let them go for Britannia.
"Who's got a suggestion?" Claude raises his hand. He is being good. "I think," he says primly, "that fighting is wrong. I don't think we should invade anywhere at all. We should make friends with the Celts."
It's ironic. All those play-time lectures have finally paid off, just in time to ruin my history happening. Because, such is Claude's standing as the hard man of the lower juniors, that the whole of Year 4 follows his lead. Not one of them votes to invade Britannia. Peace and reconcilation reign. If the Romans had had a decent team of dinner ladies, history would have been changed forever.
TUESDAY It is still raining and today's school sits in a sea of mud on the edge of Bath. The juniors are doing the Greeks, so I turn them into archeologists and set them to work to investigate the newly discovered Mudopolis. I am dismayed to see that some of the excavators are cheating. Treasures from one tray are somehow finding their way into another group's collection. But in one corner of the room a sedate group is taking turns to dig up finds with a teaspoon and brush away the sand. One little girl plucks a silver coin from the tray.
"Oh look," she says knowledgeably. "A Dracula."
WEDNESDAY I can't get into the hall straight away to set up for Pharaoh's funeral. The nursery needs it to practice for a forthcoming production. So while I light candles and get out my props, they rehearse their "twinkling".
It doesn't look that hard to me. All they do is listen to the music till they hear the right bit and then rise up on their tiptoes and "twinkle" their fingers. But it's made difficult by the fact that every child's eyes are fixed on Jessica Applegate, who is being wrapped in bandages and converted into a mummy.
THURSDAY To a village school in the lovely Wylie valley near Salisbury. Children gather in the high-windowed Victorian classrooms to watch me open my box of antique toys. As they settle in groups to play with the bone spillikins, the clay marbles, the Jacob's ladders and spinning tops, I feel as if I have slipped back 50 years. I wish I could bottle the peaceful air and take it back to Swindon to help the Claudes of this world.
FRIDAY The post brings a letter from Year 4 who were, eventually, persuaded to invade Britain. "It was good," writes Claude in neat, well-formed handwriting that looks uncannily like that of an adult helper. "I said we should invade in the winter when they weren't expecting it. We could land on a rocky shore and jump out and kill them all. And I would like to be a Roman soldier. Thank you for coming. Love Claude."
Dinah Starkey is a freelance history adviser in the West Country