Christopher Wren's Oxford triumph.
The Sheldonian Theatre was designed by Sir Christopher Wren and erected between 1664-68, immediately after the restoration of the monarchy. It was part of a plan by Wren to create one of two Italian piazzas in Oxford, the city that had been the nation's capital when Charles I fled London. The plan failed, just as Wren's plan to rebuild London on Italianate lines would also fail, but it did leave us a few wonderful buildings of which the Sheldonian is probably the best. In 1994 the European Commission described the Sheldonian as "one of the architectural jewels of Oxford".
The original purpose of the building was to provide an appropriate secular venue for the principal meetings and public ceremonies of the university. For years the university church had been finding its secular role inappropriate given the bad behaviour of undergraduates.
The name comes from Gilbert Sheldon, warden of All Souls College and later Archbishop of Canterbury. Adding "ian" was a popular way to add pseudo-classical dignity. In similar fashion Mr Ashmole' s museum became the Ashmolean and Thomas Bodley's library the Bodleian. The design of the building is loosely bassed on the Roman theatre of Marcellus, although this would have been open to the sky. Wren and Sheldon would have known this building from Sebastiano Serlio's illustrations published in 1540.
The Sheldonian is also a venue for recitals, concerts and public lectures which is how visitors get to see it. You can also be shown round (see below) but my advice would be to attend a concert to see the place at its best.
Incidentally, the first performance of Handel's oratorio 'Athalia' was given here in 1733. Handel had been offered an honorary degree by Oxford University but declined it when he found he had to pay for it to be bestowed. Realising that Oxford society wanted to hear his music - and see him in person - he organised a series of concerts instead and left the city a wealthy man!