There were six circuits in Great Domesday. Their codes and composition are:
C1: Circuit 1 comprises Berkshire, Hampshire, Kent, Surrey, Sussex
C2: Circuit 2 comprises Cornwall, Devon, Dorset, Somerset, Wiltshire
C3: Circuit 3 comprises Bedford, Buckingham, Cambridge Hertford, Middlesex
C4: Circuit 4 comprises Leicester, Northampton, Oxford, Stafford, Warwick
C5: Circuit 5 comprises Cheshire, Gloucester, Hereford, Shropshire, Worcester
C6: Circuit 6 comprises Derby, Huntingdon, Lincoln, Nottingham, Rutland, Yorkshire
C7: Circuit 7 comprises Essex, Norfolk and Suffolk, forming Little Domesday Book
For the use of codes in searching the text, see properties and property searching.