Rescue excavation became a major feature of British archaeology in the decades following the second world war when many towns and cities were being redeveloped.  Many of our cities, such as London, York and Newcastle, have been in existence for up to two thousand years, and beneath the modern city streets is a wealth of archaeological deposits.  These are in the way of the kind of deep foundations required for modern high-rise buildings. 

 

Rescue excavation takes place in the countryside too, where modern agricultural methods, new housing and quarrying are destroying traces of the past.  Rescue excavation began as a last-minute response to these dangers, but today is planned and managed more effectively as part of the redevelopment process.  Planning guidance based on legislation governs what can take place.  This gives a preference to preserving archaeology where it is (‘in situ’) wherever possible.  But this is not always feasible, and the alternative is to excavate and save the information. This is known as ‘preservation by record’, in that the archaeology should continue to be recognisable and understandable from the detailed records taken during the ‘rescue’, even though the actual site is gone.

 

Developers such as house building companies and aggregates firms are expected to bear all or most of the cost of the rescue operation.  Most professional field archaeologists in Britain are employed to carry out rescue work.  They far outnumber the people who dig for research purposes on sites which do not face a threat of destruction.