On the 12th of January 1858, the Principal Probate Registry was established. This new registry keeps a copy of every will provided as well as copies of letters of administration.
The index to these records, known as the National Probate Calendar, is available to consult at the London Probate Department. Most sections of the National Probate Calendar for 1858 to 1966 are available at ancestry.co.uk.
After the Principal Probate was established, the responsibility for probates was transferred from the complex system of church courts to a simpler system of civil probate registries. Several district probate registries were created around the country.
From then on, the registries oversaw all grants of probate and letters of administration. This collection is the Calendar of these grants.
The Calendar was separated into a different volume for each year. The entries in each volume are then alphabetised by surname.