For centuries Oxford University employed among its dignitaries a licensed buffoon, a sort of wise fool, to enliven its most important ceremonies — notably Encaenia, or the Act, the annual event at which honorary degrees are given to distinguished recipients.

He was known as the Terrae Filius, or son of the earth, and he added a certain frisson of naughtiness — even danger — to solemn proceedings, frequently going far, far too far in his satirical, ribald and sometimes obscene jibes. Terrae Filius Lancelot Addison, for instance, a so-called batteller of The Queen’s College (that is to say a member who ranked below a commoner but above a servitor) was forced to apologise on his knees for speechifying on the subject of pudenda illa obscenitate (or what Shakespeare, in a pun on the pudenda, called country matters in Hamlet).

What can he have expected, one wonders, since that was in 1658 when the Puritan Commonwealth still reigned. He might have fared better had he held off until Charles II was restored a couple of years later. But even in 1713 — by which time it seems that attempts were made to vet texts before the event — a proposed speech was publicly burned.

Names of men who held the post of official fool are known from 1591 to 1763 when the last appointment was made, and 15 of their speeches are still preserved.

Bodleian assistant keeper and diarist Thomas Hearne (1678-1735), who incidentally was dismissed for refusing to take the oath of loyalty to the Hanoverian King George I, enjoyed the fool’s satirical buffoonery of 1733. He wrote that the Terrae Filius “exposed vice and immorality, and discovered the flagrant crimes of many loose Academicians, particularly the abominable acts of some Heads of Houses”.

That year (1733), by the way, must have seen a particularly rich mixture of the sublime and the ridiculous, since Handel played the first performance of his third oratorio Athalia at the ceremony — but, famously, did not take a degree.

Mind you, Hearne was a dab hand at anarchic insubordination himself. In his diaries he referred to the Provost of Queen’s, William Lancaster, as “old smooth boots” and as “the worst vice-chancellor there ever was in Oxon”.

The diarist John Evelyn, however, had no time for the apparently unfunny joker in the pack when he attended the first degree ceremony ever to be held in the Sheldonian Theatre in 1689.

He wrote: “The Terrae Filius entertained the auditory with a tedious, abusive, sarcastical rhapsody, most unbecoming the gravity of the University, and that so grossly, that unless it be suppressed, it will be of ill consequence, as I afterward plainly expressed my sense of it both to the Vice-Chancellor and several Heads of Houses, who were perfectly ashamed of it, and resolved to take care of it in future.”

Until 1689, the Encaenia was held at the University Church of St Mary the Virgin in the High Street, but Gilbert Sheldon (1598-1677), Archbishop of Canterbury and Chancellor of Oxford University, commissioned Wren to design the Sheldonian Theatre (his first architectural project and Oxford’s first classical building) specially so that the often ribald, secular ceremonies would no longer be held on consecrated ground.

Evelyn added: “The old facetious way of rallying upon the questions was left off, falling wholly upon persons, so that it was rather licentious lying and railing than genuine and noble wit. In my life I was never witness of so shameful an entertainment.”

Poor Evelyn. Certainly that painted Sheldonian ceiling by Robert Streater, whom fellow diarist Pepys described as “a very civil little man”), has looked down upon some odd scenes.

It depicts Truth combining with Arts and Science to dispel Ignorance.