Although the British Museum was established in 1753, it first opened to the public 250 years ago this month in January 1759, in Montagu House, Bloomsbury. One of the original Trustees of the Museum was Thomas Secker, Archbishop of Canterbury between 1758 and 1768, whose portrait is featured here.

Archbishop Secker took a keen interest in the details of the Museum's foundation, with the Secker papers at Lambeth Palace Library including a printed copy of the first Orders of the Trustees, interleaved with extensive annotations from the Archbishop himself. Ever conscientious, Secker raised doubts about the constitution as it stood, complaining that the "aristocratic" form of government it proposed could turn out to be the "very worst" if future Trustees lacked the integrity of the present ones.

He did note however that, "if the Principal Librarian has a tolerable share of discernment and a good heart, he will be in himself a better system of Law than will easily be contrived". Such attention to detail is entirely in keeping with Secker's episcopacy; extremely industrious, he aimed to have a thorough grasp of the minutiae of both diocesan business and of interests relating to his wider role. According to Jeremy Gregory in the Oxford Dictionary of National Biography, "If there is a central feature of his occupation of the see it was perhaps his near obsession with paperwork" and he is remembered as a distinguished administrator. He even initiated a reordering of the printed and archival collections of his predecessors in Lambeth Palace Library, carried out by the Librarian Andrew Coltée Ducarel.

The involvement of Archbishops of Canterbury in the role of Trustee continued throughout subsequent years. The papers of Edward White Benson contain letters from the Principal Librarian and the Director of the British Museum, as well as from the bibliographer Richard Garnett, who had occasion to petition the Archbishop on the subject of immoral books within the Museum library. Later, Archbishop Lang played a key role in the famous Codex Sinaiticus being deposited in the Museum.