What came to be known as the Sheldonian Theatre was Wren's second work and was commissioned by Gilbert Sheldon, Archbishop of Canterbury.
With the triumph of the Restoration and with it the Church of England, Dean Fell, Vice-Chancellor of the University, sought to revive a project proposed in the 1630s by the late William Laud, Archbishop of Canterbury: a separate building whose sole use would be graduation and degree ceremonies.

In the past these increasingly rowdy occasions had taken place in the University Church of St Mary the Virgin, in the High Street. "
The notion that 'sacrifice is made equally to God and Apollo', in the same place where homage was due to God and God alone, was as repugnant to Fell and his colleagues as it had been to Laud"; with this in mind they approached the Archbishop of Canterbury Gilbert Sheldon, for his blessing, his assistance, and a donation.

Sheldon was forthcoming with all three.
He initially gave an impressive £1,000 (£154,128 today) and pledged to gather the needed money from like-minded sponsors.
He had little luck, however, and ultimately financed nearly the entire £14,470 (£2,230,228 today) himself, in an age where a mid-level craftsman's wage was typically between £2 and £4 per year.

Wren's initial designs for the Sheldonian probably included a proscenium stage that did not survive his revisions.
The building that was constructed was a sharp, unmistakable break from the Gothic past.
According to Wren's son, Wren designed the Sheldonian based on Serlio's sixteenth-century engraving of the D-shaped Theatre of Marcellus erected in Rome in the first century BC.

Like any Mediterranean theatre of that time, the Theatre of Marcellus had no roof: the audience relied on a temporary awning for inclement weather.
But 17th century Oxford was not ancient Rome, and the Theatre needed a permanent roof.
The span of the D-shaped roof was over 70 feet (21 m).
However, no timbers existed that were long enough to cross that distance, and Wren dismissed the obvious solution of a Gothic roof.
Instead, he decided to use the "geometrical flat floor" grid developed twenty years before by Oxford professor John Wallis.

It involved

... creating a series of trusses which were built up from shorter section[s] and held in place by their own weight, with help from judiciously placed iron bolts and plates ... [S]o effective [was the roof] that for nearly a century the University Press stored its books ..., and for many years it was the largest unsupported floor in existence ...
In 1720, surveyors inspecting the roof, following a rumour that it was no longer safe, were both surprised and impressed at what they discovered.
Though sagging slightly from the massive weight of books, the inspectors pronounced that "... the whole Fabrick of the said Theatre is, in our Opinion, like[ly] to remain and continue in such Repair and Condition, for one hundred or two hundred Years yet to come."

In November 2008 a four-year project to restore the ceiling fresco was completed.
The thirty-two oil on canvas panels originally painted by King Charles II’s court painter, Robert Streater, were removed and conserved.
As part of the conservation process, the panels had their linings replaced, holes in the canvas mended, and over-painting removed.
The allegorical story depicted in the paintings shows Truth descending upon the Arts and Sciences and expelling ignorance from the University.
What came to be known as the Sheldonian Theatre was Wren's second work and was commissioned by Gilbert Sheldon, Archbishop of Canterbury. With the triumph of the Restoration and with it the Church of England, Dean Fell, Vice-Chancellor of the University, sought to revive a project proposed in the 1630s by the late William Laud, Archbishop of Canterbury: a separate building whose sole use would be graduation and degree ceremonies.
In the past these increasingly rowdy occasions had taken place in the University Church of St Mary the Virgin, in the High Street. "The notion that 'sacrifice is made equally to God and Apollo', in the same place where homage was due to God and God alone, was as repugnant to Fell and his colleagues as it had been to Laud"; with this in mind they approached the Archbishop of Canterbury Gilbert Sheldon, for his blessing, his assistance, and a donation.
Sheldon was forthcoming with all three. He initially gave an impressive £1,000 (£154,128 today) and pledged to gather the needed money from like-minded sponsors. He had little luck, however, and ultimately financed nearly the entire £14,470 (£2,230,228 today) himself, in an age where a mid-level craftsman's wage was typically between £2 and £4 per year.
Wren's initial designs for the Sheldonian probably included a proscenium stage that did not survive his revisions. The building that was constructed was a sharp, unmistakable break from the Gothic past. According to Wren's son, Wren designed the Sheldonian based on Serlio's sixteenth-century engraving of the D-shaped Theatre of Marcellus erected in Rome in the first century BC.
Like any Mediterranean theatre of that time, the Theatre of Marcellus had no roof: the audience relied on a temporary awning for inclement weather. But 17th century Oxford was not ancient Rome, and the Theatre needed a permanent roof. The span of the D-shaped roof was over 70 feet (21 m). However, no timbers existed that were long enough to cross that distance, and Wren dismissed the obvious solution of a Gothic roof. Instead, he decided to use the "geometrical flat floor" grid developed twenty years before by Oxford professor John Wallis.
It involved

... creating a series of trusses which were built up from shorter section[s] and held in place by their own weight, with help from judiciously placed iron bolts and plates ... [S]o effective [was the roof] that for nearly a century the University Press stored its books ..., and for many years it was the largest unsupported floor in existence ...
In 1720, surveyors inspecting the roof, following a rumour that it was no longer safe, were both surprised and impressed at what they discovered. Though sagging slightly from the massive weight of books, the inspectors pronounced that "... the whole Fabrick of the said Theatre is, in our Opinion, like[ly] to remain and continue in such Repair and Condition, for one hundred or two hundred Years yet to come."
In November 2008 a four-year project to restore the ceiling fresco was completed. The thirty-two oil on canvas panels originally painted by King Charles II’s court painter, Robert Streater, were removed and conserved. As part of the conservation process, the panels had their linings replaced, holes in the canvas mended, and over-painting removed. The allegorical story depicted in the paintings shows Truth descending upon the Arts and Sciences and expelling ignorance from the University.
Sheldonian Theatre