“The colonel is a steadfast man, me thinks he will keep for the king, aye.”

But Colonel Prichard’s steward is wrong. It won’t be long before the master of Llancaiach Fawr Manor - despite a visit from Charles I - switches sides in the Civil War, and goes over to the Parliamentarians. But in 1645 the signs of such a shift were not obvious, even to those working closely with him.

The steward and the other servants who show you round this fine semi-fortified Tudor manor house, set in the countryside near Treharris in the Rhymney Valley, are, in fact, actorinterpreters, entering with gusto into their roles in this Living History Museum of the Civil War years, .

As we’re led through kitchens, parlour, bedchambers, the birthing room, study and great hall, the servants tell us not only about the rooms and their contents, but about their own lives and conditions, the local feuds and gossip, their thoughts about their master and mistress (“A peevish woman”) and the inevitable ghost said to haunt the house.

The tour is both entertaining and informative. In the kitchen we learn how to cook crow pie, and hear how pomander protected people against the plague. In the parlour we admire a chair made of bobbins, and see where the claret is kept warm behind the Welsh oak panelling. In the birthing room we hear how, even with a difficult pregnancy, the physician is not allowed in, but has to give his instructions from outside the door.

In each room, the servant in charge invites us to ask questions; none seems to be short of an answer. To achieve this authenticity, the actors have absorbed a huge amount of information - not just on their own character, but also on the rest of the household, on local traditions and customs, and on contemporary ideas about national politics and religion.

They’ve also studied closely the structures and idioms of 17th-century language. There’s no script, so they need to think on their feet, but also avoid slipping out of role. ‘We want to create a bubble of illusion to draw people back into the past,’ says Val Williams, the museum’s education manager. “Children enjoy the method: we find they’re less inhibited than adults at asking questions, whether they’re quite mundane, or to do with issues of life and death.”

The museum has proved immensely popular since it opened in 1991: last year it attracted 66,000 visitors, of which a third were children in school groups. The visits and activities are primarily geared to key stages 1-3 in the core subjects, but nursery school children are also catered for. All supervising adults are admitted free, and teachers can make a preliminary visit without charge.

Val Williams is convinced of the value of the living history approach. “It’s a marvellous way of bringing alive demographic data such as infant mortality rates,” she says. “Teachers tell us that children have performed better back on school on tasks relating to topics they’ve covered here.”

o Llancaiach Fawr Manor, Nelson, Treharris, Mid Glamorgan, CF46 6ER. Tel: 0443 412248.