Rediscovering the Great Sacristy

The excavation was completed in August 2020 having met its aims to:

• Fully expose and record the superstructure of the 13th-century Great Sacristy so that its construction, internal arrangement and later alterations will be understood
• Record the Abbey’s walls and buttresses which have been covered with earth since the medieval period
• Investigate the natural topography of the site, developing our understanding of Thorney Island, the name given to the outcrop of land upon which Westminster Abbey was built
• Investigate and date remains pre-dating the Great Sacristy, such as early burials
• Understand how the site was developed once the Great Sacristy was demolished in the 1740s

In the 13th century, the late 11th-century church built under Edward the Confessor was completely rebuilt under the reign of Henry III. The masons constructed massive lime-concrete raft foundations to build most of the church that stands today. Prior to the 13th-century rebuilding, the site of the North Green was used as a burial ground for monks. In 1251, as part of Henry III’s work, an L-shaped building known as the Great Sacristy was constructed here.

In 1869, under the direction of Sir George Gilbert Scott, who was then Surveyor of the Fabric, the Abbey’s mason Henry Poole was instructed to 'remove from the North Green the earth and rubbish which had accumulated there for several centuries'. During the removal of this material the remains of the Great Sacristy were revealed. Poole recorded the remains and illustrated them as an L-shaped structure.

The plan shows that the building had a square room at its eastern end. It is believed that access to this room was via a door from the North Transept, and that access to the remainder was via the extant North Door in the Abbey’s nave.

The work also revealed stone-lined graves of early medieval burials, and a Roman sarcophagus, excavated in 1869 and now on display in The Queen’s Diamond Jubilee Galleries, which had been reused for a medieval burial, most likely in the 11th century.

The Great Sacristy is thought to have had several functions. Vestments and other precious objects may have been stored in the square room at the eastern end, and the building’s distinctive L-shape provided a space where the clergy could prepare before processing into the church. Maintenance sheds, used for laundry and candle making, were located in the enclosed yard to the rear of the building.

Records show that a second floor was added to the Great Sacristy in the 1380s when many other new buildings were erected across the wider monastic complex.

After the monastery was dissolved c.1540, the Great Sacristy was repurposed as a domestic dwelling for Prebends (administrative staff of the Abbey). However, by 1616 the Sacristy building was described as 'very ruinous and standeth in very great need of present reparations'.

A further period of repair work was enacted in the 1710s and 20s and at this time the Surveyor of the Fabric, the famous Sir Christopher Wren, reported that 'the houses on the North side are so close [to the Abbey], that there is not room left for the raising of scaffolds and ladders'.

The decision to demolish the former Great Sacristy and the other buildings in this area was taken in the 1740s, for a number of reasons including the cost of their upkeep and because they impeded much needed repairs to the Abbey's nave and northern transept.

Many interesting archaeological features have been revealed during the excavation, including the masonry wall foundations of the Great Sacristy and the Abbey, evidence of post-medieval structures and numerous burials dating from the 10th to the 19th century.

Looking north from the roof of the Abbey, the foundations of the L-shaped building Great Sacristy can be seen (below). The southern wall foundation is much narrower than the external wall foundation to the north. This suggests that the southern wall of this building was probably half-timbered, requiring a less substantial foundation, whereas the outer northern wall may have been built entirely from stone.

A lead pipe has been discovered protruding from the wall of the nave. This pipe would have supplied water to the monastery and may date to the 13th century.

The archaeological works have revealed that masonry from an earlier building, probably Edward the Confessor’s church, was reused to build the foundations of the 13th century Abbey.

A brick post-medieval cess pit was found located between two of the nave buttresses. The backfill of the cess pit contained a large assemblage of early 18th-century domestic objects including china plates, chamber pots, glass drinking vessels and an assortment of combs and brushes. The cess pit would have served a latrine associated with townhouses located to the west of the Great Sacristy building.

Many fragments of medieval painted wall plaster have been found. These fragments may suggest that the internal walls of the Great Sacristy were decorated with hand painted red, white and black flowers.

Hundreds of burials have also been discovered on the North Green site.

Some pre-date Henry’s church, such as this remarkably-well preserved chalk-lined grave believed to be that of an 11th-century monk. Others date from as late as the 18th century when the North Green was used as a burial ground for St Margaret’s Church.

The North Green excavations are the first stage of a long-term project to transform the welcome we offer to visitors and restore the Abbey. Eventually a new building will be constructed on the site of the former Sacristy to house welcome, ticketing and security facilities, allowing all visitors to follow in the footsteps of kings, queens and royal brides and enter the Abbey by the Great West Door.