Corfu (modern-day Keryka, Greece) with its strategic position at the southern end of the Adriatic Sea was first occupied by the Venetians in 1401 having passed through a series of hands since was taken from the Byzantines in 1081 by the Norman Robert Guiscard. Venetian forces withstood a number of major attacks by the Ottomans most notably in 1537, 1571 and 1716. The first defences were built in the sixth century on two rocky outcrops on a peninsula which dominated the bay and harbour to the south and were maintained and extended throughout the middle ages. In the sixteenth century the land front was constructed with two bastions'joined by a curtain with a central gateway all fronted by a sea water moat. Following the 1571 siege the developing town was further protected by a large fortification built on a hill just over a kilometre further west. This consisted of two large connected bastions fronted by a wide terrace. The town itself was also fortified by a trace consisting of a large shallow bastion, a central rectangular bastion, an acute angled bastion at the southern corner and a smaller bastion against the coast. This work was initially carried out by the engineer Vitelli, in the mid-seventeenth century these works were extended with outer trace containing two bastions and three demi-lunes'and beyond them two detached earthwork forts.
The sculptor has had to resolve a number of difficult issues on this panel. The main defences of the old fort are shown in plan whilst the two rocky eminences which bore the earlier fortifications are shown in elevation, one behind the other. The view is from the north and the works of the new fort are sketchily shown crammed into the bottom right corner. On the other hand the northern most bastion of the town trace is clearly presented as is the demi-lune beyond it and the squared bastion next in line, however, lack of space means that the southern most defences are again quite restricted. In the bottom left corner are shown two galleasses, one under way and other in the harbour with its sail furled. The surviving fortifications on Corfu today are some of the best preserved and most impressive in the eastern Mediterranean.