One of the many notable results of the Maiden Castle excavations was the formulation of the ‘Sling-stone theory’ to account for the building of multiple ramparts round Early Iron Age camps. The excavations revealed that the Iron Age A2 camp, at first on the eastern knoll only, but later extended to include the whole hill, was surrounded by a single rampart, and that this, at some period in the 1st century B.C., was suddenly reinforced and encircled by two outer ramparts, thus producing the massive defence works to be seen today. The nature of the construction of the new defences led the excavators to the conclusion that they were the work of a ‘foreign dynasty’ of, invaders of the fort, and not of the A2 inhabitants. It was found, however, that this ‘sudden structural change’ was not associated with a similar sudden cultural change, as might have been expected. There was a change, represented by the introduction of the first traces of Iron Age B pottery, but this was slight at first and only gained in importance with the passage of time. The A2 pottery remained but became more and more influenced by the B forms until the latter gradually became ‘dominant and characteristic’.