York Historic Environment Record

Three separate areas were excavated. Trench 1. A small investigation in the Mansion House cellar, Trench 1, measuring just 1 metre square, revealed that the brick floor of the cellar was laid directly onto ‘natural’ deposits, laminations of silt and clay laid down towards the end of the last glaciation about 10,000 years ago. Any more recent layers had been completely removed by the digging of the cellar in 1725. Trench 2. Trench 2, was excavated in Common Hall Lane. This medieval lane runs from a watergate right at the edge of the River Ouse underneath the northern half of the Guildhall, towards St Helen’s Square and Stonegate. Rarely visited due to its tendency to flood, the very existence of this atmospheric below-ground passageway excited much public and media interest. Trench 2 was located on the southern side of the lane, hard against the stone wall and piers which support the timber columns of the Guildhall’s north aisle immediately above. Five metres in length by one metre wide, Trench 3. The 5.0m x 1.5m excavation in Guildhall Yard, Trench 3, was dug to establish how intact or otherwise archaeological strata in this area are, and the levels of successive medieval and later ground surfaces in front of the Guildhall. The present ground surface in the yard slopes downwards to the Guildhall’s main entrance; had that always been the case, or was this slope the result of very recent landfilling? When excavation began it quickly became apparent that medieval deposits beneath the Yard were largely intact. The earliest layers reached, on present assessment of the evidence dating from the 12th/13th centuries, were of a type familiar from many archaeological sites in York: the muddy, bare-earth back-yards or ‘backlands’ often found behind medieval street-front properties, in this case on Coney Street. This muddy backland was transformed by the construction of two substantial walls, surviving as footings about three metres apart which were aligned parallel with the front of the Guildhall. The more easterly of these was mortared, the other, closer to the Guildhall, was not. The ground surface associated with the mortared wall was at a level close to that of the threshold of the main door of the Guildhall, and may have formed part of one of two other buildings documented as having been built at the same time in the 1440s – a chapel and a maison dieu. The latter is a term which refers to almshouses or a ‘hospital’, in the sense of a place of hospitality for the poor and needy, rather than an establishment with its modern, specifically medical, connotations. This archaeological evidence also suggests that the medieval Guildhall Yard was a level, rather than a sloping, surface. These buildings seem to have stood until 1725, when they were demolished to be replaced by the present Mansion House. In the course of the 17th century, however, the maison dieu had been converted into a place offering a rather different form of hospitality – the Cross Keys public house! Spanning this period the excavation revealed a series of external yard surfaces and possible internal floors. With the construction of the Mansion House the area seems to have been left as an open, cobbled yard, until late in the 19th century when it was given over to a garden or shrubbery, concealing beneath it a deep, wide drain or culvert. The asphalt of the existing yard surface and its brick rubble bedding were laid over the top of this garden soil.