Tavira is unusual in that the town has occupied three different sites in its long history. In his lecture, Peter will show why the town moved position and he will estimate when it came to its present location. Also important to the present shape of the town are the castle and the walls (some of them Muslim in origin) together with its military buildings. The old bridge has the reputation of being Roman, but this idea is not correct; when was it built? There is a very pleasant garden next to the river (Jardim do Coreto), but it has not always been there. What did it replace? How did the town assume its present shape? Tavira has the eputation of possessing thirty one churches. It has not so many, but still more than any other town in the Algarve. Why? How important has Tavira been in the history of Portugal? Peter has been interested in the history of his adopted town for the sixteen years he has lived in the Algarve, and he brings his Cambridge historical education to bear on the fascinating story of Tavira. This lecture is the first of two, and in the second lecture later in the year, Peter will examine the social and economic history of the town.