sentences:  Sergius & Bacchus's construction, the Sasanian-influenced Church of St Polyeuctus - the largest church in Constantinople until Hagia Sophia's construction - was likely the most direct influence.Even so, because Anicia Juliana's St Polyeuctus, built 519-522, was not domed with brick but instead covered three opposing pairs of exhedrae with a wooden roof typical of a basilica, the immediate architectural precedent of both SS.Sergius & Bacchus and Hagia Sophia must be found in pendentive domes elsewhere, such as in the so-called Mausoleum of Galla Placidia in Ravenna and the several earlier Byzantine domes rotundas and polygons whose foundations survive.