The Sheldonian, therefore, commonly known in Oxford as 'The Theatre', will be spoken of first, although it is the last in date of construction. It is a memorial at once of the munificence of one of the greatest among Oxford's many episcopal benefactors, and also of the architectural skill of her most eminent architect, Sir Christopher Wren. Down to the time of the Civil War, the ceremony of the 'Act' (cf. p. 27 seq.) at which degrees were conferred, had taken place in St. Mary's; but the influence of the Puritans was beginning to affect all parties, and was causing the growth of a feeling that religious buildings should not be used for secular purposes. John Evelyn, who gives us our fullest account of the opening ceremony at the Sheldonian, notes that it might be thought 'indecent' that the Act should be held in a 'building set apart for the immediate worship of God'[30], and this was 'the inducement for building this noble pile'. Wren had shown his design to the Royal Society in 1663, and it had been much commended; he was only a little more than thirty years of age, and it was his first public building, but he was already known as that 'miracle of a youth' and that 'prodigious young scholar', and he fully justified the Archbishop's confidence in him. So great was this that Sheldon told Evelyn that he had never seen the building and that he never intended to do so. Wren showed his boldness alike in the style he chose--he broke once for all with the Gothic tradition in Oxford--and in the skill with which he designed a roof which was (and is) one of the largest unsupported roofs in England. The construction of it was a marvel of ingenious design. [Sidenote: Its Dedication.]