In the high summer of 1675 building work finally began on the new Cathedral of St Paul, after nine years of drawings and deliberation by its architect, Dr (and by then Sir) Christopher Wren. The history of those nine years does not need recapitulation, but the reader may be reminded that after the making of several distinct designs and the First and Great Models Wren had become secretive and had privately obtained the sanction of King Charles II to make ‘some Variations, rather ornamental than essential, as from Time to Time he should see proper’, that a royal warrant had notwithstanding been issued on 14 May 1675, approving the set of drawings now consequently known as the Warrant design, and that by a process of metamorphosis which can be only partly retraced, Wren distilled from that pragmatic but generally unloved design another, now known as the Definitive, on which work finally began.