The ogee arches present over a  number of portals around San Marco are emulations of Islamic arches found on both secular and religious buildings throughout the Middle East.  An ogee arch “is characterized by its double continuous curve passing from concave to convex” and was used throughout the Islamic world beginning as early as the third century.

This type of arch was not found on any other European structures except for  those in Venice, and differed from the commonly seen, rounded arches of the West with a Roman precedence.[1. Deborah Howard, Venice and the East: The Impact of the Islamic World on Venetian Architecture 1100- 1500, (New Haven: Yale University Press, 2000), 142.]  In the thirteenth century, the ogee arches were added to the exterior of San Marco above the Porta dei Fiori on the north facade, above the window of the Capella Zen Chapel on the west façade, and above the Porta San’ Alippio on the West facade.

The arch above the Porta dei Fiori can be considered a variation on the ogee arch because it passess from concave to convest twice before it culminates in a point.  These ogee arches were seen throughout the Middle empire by Venetian merchants and  when added to the exterior of San Marco,  they symbolized Venice’s economic connection in the Middle East.