Burne-Jones spent some time studying and copying the marble pavement in the cathedral of Siena in the Spring of 1873. The sketches he made, evidence of the time spent, is shown the sketchbook (no. 64 - Fitzwilliam Acc. No.10705 - 1873 ). In the pavements there are ten figures representing the various Sibyls, of whom five re-occur in Michelangelo's frescoes in the Sistine Chapel, which Burne-Jones also studied. On receiving a large commission to fill the windows of Jesus College Chapel, Cambridge, in the following Autumn, Burne-Jones drew upon his experience and included the Sibyllas Delphica, Cimmeria, Persica, Cumana, Phrygia, Libyssa, Erythraea, and Tiburtiana. He was here manifesting himself as academically sound, justifying his commission for the Chapel associated with an academic establishment.