An unusual sight welcomes the group visiting Hedingham Castle in Essex - standing on the Tudor bridge, where there was once a drawbridge, is Empress Matilda, her long, golden dress shimmering in the sunlight. For the past five years, Sylvia Horden has brought history alive by playing the role of the queen, and pupils from St Nicholas School, Harlow, listen as she relates the history of the castle and her part in it as the daughter of Henry I and how she fought for the crown with her cousin, Stephen.

“After the Battle of Hastings in 1066, William the Conqueror rewarded one of his favourite knights, Aubrey de Vere, with quite a lot of land,” she explains. “His son built Hedingham Castle on this land around 1140 and its keep is considered to be the finest and best preserved in England.”

The visit links with the national curriculum: from looking at the castle as a home, medieval warfare and the Normans, to how the impact of the Conquest affects our lives today. The wealth of the de Vere family is evident from the building material, Barnack stone, which was quarried in Northamptonshire and used to build Norwich and Peterborough cathedrals. In the 12th century, the area around the castle would have been left open so attackers could be seen, but today the grounds are full of trees and shrubs, and the lawns are ideal for children to eat lunch after their visit.

Hannah Davis, 12, is impressed with the castle’s defences. “It would have been very hard to shoot arrows through those tiny slit windows,” she says.

Empress Matilda leads the pupils through the castle entrance and to the ground floor where the food was stored. Two enormous wooden doors have been added, as this room was once used as a garage. “But this destruction of the walls did us a huge favour for it allows us to see just how solid the castle walls were,” says history teacher Maureen Pantall, pointing to the four-metre thick walls. She explains how, during a siege, the inhabitants were able to eat fish from the lake by way of a secret tunnel.

Next, the children make their way to the top floor, known as the dormitory floor, which would have been used by the earl and his wife for sleeping.

The walls are decorated with banners, including one of King John, who besieged the castle in 1216. The pupils regroup in the banqueting hall to listen to more tales from Empress Matilda. This magnificent room contains an 8.5-metre arch, one of the largest built in Norman times, and running round the top section is a minstrels’ gallery. The pupils are fascinated by the garderobe, or toilet, in an alcove where the waste would fall to the septic pit two floors below.

Empress Matilda describes how the room must have looked during a banquet and how it would have sounded with jesters, acrobats and musicians. The children also learn that instead of a chimney, the smoke from the huge fireplace escaped through vents.

Later, she surprises the girls with her tales of Norman hairstyles: “Hair extensions are older than you think, for long hair was considered beautiful in Norman times and many women would wear plaits and use extensions with hair cut from their servants.”

Hedingham Castle seemed to excel most expectations. The favourite part of the visit for 12-year-old George Cole was seeing the small, claustrophobic dungeon, and he was surprised by the number of stairs in the spiral staircase leading to the top of the castle.

Harry Scott, 12, is also impressed with what he has seen. “I hadn’t expected it to be so well preserved,” he says, “and my favourite bits were seeing the weapons and the main hall.”