History of the trulli.
There is evidence of prehistoric settlement in the Itria valley, and it is possible that the tholos tradition of building may have come to the region at this time. It is generally considered that the present settlement dates from the mid-14th century, when what appears at the time 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 such as nearby Noci, allowing them to build cottages known as easel/e. However, recent research by local planners suggests that scattered rural settlements that began around AD 1000 on either side of the small river that now runs underground through the town 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 that 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 no more than a minimal physical response to local conditions and circumstances, later to be exploited for fiscal or punitive purposes.
By the mid-16th century the Monti area was already occupied by some forty trulli, but it was in 1620 that the settlement, then still part of the town of Noci, began to expand, when the Count of the period, Gian Girolamo Guercio, ordered the construction of a bakery, a mill, and an inn. By the end of the 18th century the community numbered over 3500 people, and in 1797 they succeeded in bringing the feudal rule of the Acquaviva family to an end by obtaining the status of royal town from Ferdinand IV, Bourbon King of Naples. The name of Alberobello was adopted, taken from the medieval Latin name of the region, silva arboris belli. From this time onwards the construction of new trulli quickly declined.