Much of the city centre had been abandoned .
Much of the city centre had been was turned into a cemetery , while the centre of habitation had moved to the southwest of the city , where a new wall was built to contain the abridged Roman town .
Much of the city centre had been abandoned and was turned into a cemetery , while the centre of habitation had moved to the southwest of the city , where a new wall was built to contain the abridged Roman town .