There was no systematic instruction in Agriculture at the University until 1908 when the School of Rural Economy was established and the first full time Professor of Rural Economy was appointed. However, an agricultural chair (the earliest in an English University) had been founded and endowed in Oxford in 1796 by the bequest of John Sibthorp. Upon his death, Sibthorp left his property at Sutton and Stanton Harcourt to the University and the income from this was to be devoted to the publication of his Flora Graeca; after its publication had been completed, the annual sum of £200 was to be used to found a chair of Rural Economy, the holder of which was to be the Sherardian Professor of Botany. Owing to the expense of publishing Flora Graeca the first appointment to the Sibthorpian Professorship was not made until 1840 when the then Professor of Botany, Charles Daubeny, also became the Sibthorpian Professor of Rural Economy. The terms of Sibthorp's will demanded that Daubeny read a public lecture on Rural Economy each term and appropriate part of his garden to the cultivation of plants used in agriculture and the arts.

Following the Universities of Oxford and Cambridge Act, 1877, the University of Oxford Commissioners separated the two professorships of Botany and Rural Economy by Statute in 1882. The endowment of £200 for the foundation of a professorship of Rural Economy was a comparatively small amount and meant that only a 'Visiting Professorship' could be established. The holder of the now separated post was to give twelve public lectures annually on agricultural subjects. The first holder of office was JH Gilbert who was appointed in 1884. In 1907, St John's College increased the endowment of the Sibthorpian professorship sufficiently to enable a full-time Professor to be appointed. It was from this that the Department of Agriculture took its origin and the first full-time Professor of Rural Economy was William Somerville.

The School of Rural Economy was established in buildings erected on Parks Road; much of the finance for this and the site was provided by St John's College. From 1908, students could take a two year course leading to a Diploma in Rural Economy; this course existed until 1918 when a Final Pass School was instituted enabling agricultural students to obtain the Bachelor of Arts degree. Postgraduate students could still obtain a Diploma in Rural Economy after following a course of specialised study.

During the 1920s the School struggled with problems of low numbers and poor quality of undergraduates and by 1931 the existence of the School was under threat. In 1937, as a result of hard lobbying and persuasion by the University, the Ministry of Agriculture approved the idea of elevating agriculture from a Pass to a Final Honour School. With the institution of an Honour School, the syllabus was altered and the study of the evolution of agriculture became as important as the economic and scientific aspects.

The establishment of the Final Honour School was not fully implemented until after the Second World War. In 1947, the Diploma in Rural Economy was discontinued as it had in effect been replaced by the Diploma in Agricultural Economics available at the Institute for Research in Agricultural Economics.

The Institute for Research into Agricultural Economics was established in 1912 and formed a part of the School of Rural Economy. It was founded as a joint venture by the University and the Board of Agriculture to investigate problems in Agricultural Economics, and was partly financed by an annual grant from the Development Commission. The Institute occupied premises in Parks Road and initially provided some teaching of students who were reading for the Diploma in Rural Economy and afterwards those reading for the Pass School in Rural Economy. Following the reorganization of University statutes concerning the administration of the School of Rural Economy in 1945, the Institute became an independent body. Its records are also held by the University Archives

In addition to the Honour School in Agriculture, and the Diploma in Rural Economy, the School of Rural Economy also offered a Certificate of Proficiency in Estate Management although this only existed from 1937 to 1946.

In 1945 the School of Rural Economy changed its name to become the Department of Agriculture and a new Faculty of Agriculture and Forestry was created. As the School grew, it needed more space and resources, so after the Second World War the buildings on Parks Road were extended and altered and a University Field Station of 350 acres was established at Wytham in 1956.

From its foundation in 1908 to 1926, the School of Rural Economy was in the Faculty of Natural Sciences. In 1926, this Faculty was divided and the School of Rural Economy was placed in the Faculty of Biological Sciences. It remained here until 1945 and the creation of the new Faculty of Agriculture and Forestry. In 1968, the Faculty of Agriculture and Forestry was abolished and Agriculture and Forestry became sub-faculties of the new Faculty of Biological and Agricultural Sciences. At the same time, the Department of Agriculture changed its name to become the Department of Agricultural Science.

In 1970, a new three-year honours degree in Agricultural and Forest Sciences was established in which the Departments of Agricultural Science and Forestry and the Institute of Agricultural Economics were involved. This meant, firstly, that undergraduates were now offered a BA Honours degree in Agricultural and Forest Sciences and, secondly, the phasing out of the separate Honour Schools of Agriculture and Forestry.

In 1981 the University Grants Committee (UGC) cut the resources available to Oxford (as to all Universities) and recommended that the Honour School of Agriculture and Forest Sciences be discontinued but that the number of students in biological sciences be increased. After much debate the Board of the Faculty of Biological and Agricultural Sciences decided that the Honour School of Agriculture and Forest Sciences would be abolished after the examination in Trinity Term 1985 and therefore the undergraduate intake for 1982 was the last. Following the recommendation of the UGC that the number of students in biological sciences should be increased, a new examination in Pure and Applied Biology was introduced into the Honour School of Natural Science for the first examination in Trinity Term of 1986.

The field station at Wytham was transferred to the new Department of Plant Sciences upon its formation in 1985. The Department was created by combining the former Departments of Agricultural Science, Botany and Forestry.

The title of Sibthorpian Professor of Rural Economy was converted to Sibthorpian Professor of Plant Sciences by an order in Hebdomadal Council in August 1989.

Sibthorpian Professors: