The modern county comprises the old counties of Cambridgeshire, Isle of Ely, Huntingdonshire and Soke of Peterborough. Cambridge Family History Centre , LDS Church, Cherry Hinton Road, Cambridge IGI, many records on microfilm and access to the whole resources of the organisation. Bishops' Transcripts are kept at Cambridge University Library, West Road, Cambridge.
Indexed transcripts exist of many sets of parish registers and more are in progress.
Copies are available at CRO and usually also the SOG Library in London. A Search Service is available. Probate records 1858 on - all records are kept at the Principal Probate Registry, Somerset House, London. Indexes available, some published. Probate records for some parishes around Newmarket to 1837, when transferred to Ely, are kept at Suffolk RO, Bury St Edmunds.