Prior to 1858 jurisdiction over testamentary matters was exercised by the Church of England and was most commonly administered through the consistory court of the local diocesan bishop. This court was presided over by the spiritual chancellor of the diocese, with the day- to-day running of the administration being carried out by the diocesan registrar centrally, and by local surrogates throughout the diocese. Further information on the pre-1858 probate jurisdiction of the church courts is included on the North East Inheritance project website .
The Probate Act of 1857, which came into force on 12 January 1858, transferred jurisdiction over testamentary matters from the Church of England to the state, and also provided for the establishment of District Probate Registries and of a Court of Probate. The Court of Probate later became the Probate Division of the High Court, which is now the Probate Service within the Family Division of the High Court. The Durham District Probate Registry, which was situated in Durham City, dealt with probate matters for the whole of County Durham until 1926. From 1926 to 1969, it served County Durham excluding Gateshead and some other areas on the south bank of the river Tyne, which were transferred into the jurisdiction of the Newcastle upon Tyne District Probate Registry. The Durham Probate Registry closed in 1969, when most of its records were transferred to the York Sub-Registry.
From the guide to the Durham Probate Records, ca. 1526-1940, (Repository Unknown)