Alberobello, the city of drystone dwellings known as trulli , is an exceptional example of vernacular architecture. It is one of the best preserved and most homogeneous urban areas of this type in Europe. Its special features, and the fact that the buildings are still occupied, make it unique. It also represents a remarkable survival of prehistoric building techniques.
There was prehistoric settlement in the Itria and the tholos (dome-shaped tomb) tradition of building may have come to the region at this time. The present settlement dates from the mid-14th century, when what appears to have been an uninhabited area was granted to the first Count of Conversano by Robert d’Anjou, Prince of Taranto, in recognition of his service during the Crusades. He and his successors colonized the area by moving people from their other fiefs, allowing them to build cottages known as caselle . However, recent research suggests that scattered rural settlements that began around AD 1000 gradually coalesced to form the village units of latter-day Aja Piccola and Monti. Tradition has it that drystone walling was imposed upon the new settlers so their houses could be quickly dismantled. This served two purposes: recalcitrant householders could be dispossessed easily and, later, it would be possible to avoid taxation on new settlements. In the latter case the buildings could be reconstructed equally rapidly. This is known to have occurred in 1644 to thwart tax inspectors sent by the King of Naples. However, historical and comparative analysis suggests that this technique was a minimal physical response to local conditions, later to be exploited for punitive purposes.