See also: Quarter Sessions
Before 1971 most serious crimes were tried before pairs of professional judges who went on circuits through groups of counties, holding 'assize' sessions in each county twice a year. The Quarter Sessions Court would refer serious or difficult cases up to the assizes; conversely, cases not dealt with by the assize judges before moving on to the next county were left with the Quarter Sessions, so the jurisdiction of the two courts often coincided.
The assize circuits had their own Clerks of Assize who kept all the records, which ultimately found their way to the National Archives (former Public Record Office); many of the assize records for Cambridgeshire and Huntingdonshire are therefore now at TNA. An Assizes Research Guide is available on their website - go to the "Getting Started" section for an index of their guides.
Cambridgeshire and the Isle of Ely
Cambridgeshire was part of the Norfolk Circuit up to 1876 and the South Eastern thereafter. Practically all assize records for the county are held at the National Archives in Kew. The Isle of Ely had its own separate assizes, held at Ely and Wisbech until 1836, when the Bishop of Ely's temporal jurisdiction over the Isle was abolished.
Minute books for the plea side (civil business) 1801-1836 and the Crown side (criminal business) 1801-1836 are among records of the Clerk of the Peace deposited at Cambridgeshire Archives.
There also papers concerning assize cases c. 1792-1822 among the records of the Chief Bailiff of the Isle of Ely [283/] and calendars of prisoners for trial at the Ely Assizes, 1825-1835 [Ely UDC].
Cambridge University Library holds Plea rolls and gaol delivery rolls for the Isle of Ely Assizes from the 15th - late 18th century.
The Assizes Held at Cambridge AD 1260, W. M. Palmer (1930) is a condensed translation of the Cambridgeshire assize roll for that year with an informative introduction.
Huntingdonshire
Huntingdonshire was on the Norfolk Circuit until 1876, and on the South Eastern Circuit thereafter. The majority of the surviving records are at the National Archives. However, some records of the Huntingdonshire assizes (especially from the reign of Charles II) appear to have remained within the county. These records eventually made their way via Councillor Tebbutt and the Norris Museum in St Ives to Huntingdonshire Archives in 1955 (accession 251) where they were catalogued with the records of the Clerk of the Peace, even though the two Clerks were in principle different officials.
Huntingdonshire Archives holds the assize rolls for 1653, 1660-1688, and 1694; the rolls include writs, indictments, bonds, and coroners' inquests. Some extracts from the assize rolls were published by C F Tebbutt in Extracts from Assize Rolls of Huntingdonshire ; a copy is available at the Record Office for reference.