Medieval building stone at the Tower of London
By Tim Tatton-Brown
London Archaeologist, Vol.6-13 (1991)
Introduction: Although much has been written about the Tower of London and its buildings, the different types of building stone used have been largely ignored. This is perhaps because there has been a vast amount of post-medieval rebuilding and refacing. However, much original masonry of many different phases remains; this can be supplemented by the documentary sources which often mention the building stone, its cost, and its source. In January 1990 a small group of geologists and archaeologists visited the Tower and examined original areas of masonry in many structures, thanks to the help of the authorities. This brief article summarizes our observations.
Apart from the Roman city wall (largely built of Kentish Ragstone), the great early Norman keep, later known as the White Tower, is the earliest masonry building surviving at the Tower. UnforApart from the Roman city wall (largely built of Kentish Ragstone), the great early Norman keep, later known as the White Tower, is the earliest masonry building surviving at the Tower. Unfortunately most of the external ashlar masonry is a refacing of Portland Stone in the 18th century. At this time almost all the quoins, and the doors and windows, were completely refashioned. Inside the White Tower, however, it is possible to see quite a lot of original ashlar masonry, and perhaps the best place is in the exceptionally fine chapel of St John. Here the main material is Caen Stone, from Normandy, which first came into England at this time (the later 11th century). Caen Stone is not, however, the only material. A careful look at the masonry shows that there is another slightly darker type of stone, which on closer examination is seen to be packed with casts of broken shells. This is Quarr Stone from the north-east corner of the Isle of Wight, which was used much nearer to its source at this time (for example, in the contemporary Winchester Cathedral), but which soon became scarcez. After this time, it is not found in London, although a similar stone from the Isle of Wight was brought to the Tower in the later 13th century (see below). In the north-east part of the White Tower, some Reigate Stone is also seen, but these blocks are almost certainly later medieval repairs. Documents tell us that in 1248 Henry I11 ordered ‘all the leaden gutters of the Keep, through which the rainwater shall fall from the top of the same tower, to be carried down to the ground; so that the wall of the said tower, which has been newly white-washed, may be in no wise injured by the dropping of rainwater. Hence its name: The White Tower.