The Roman city walls - of brick, masonry and cement -were raised and further fortified in the third and fourth centuries A.D. By their remains one can trace the boundary of the original Roman settlement of Barcino. The Capilla de Santa Águeda [chapel of Saint Agatha], Palau Reial Major, with crown-shaped octagonal belltower, was begun in 1302 at the behest of Jaume II (the Just), King of Aragon and Valencia and Count of Barcelona (1291-1327). The walls of the chapel of Saint Agatha straddle the Roman walls at one side, the space needed by the burgeoning medieval city outgrowing the confines of the Roman oppidum.
