The story of Alberobello is truly unique and curious. The Counts of Conversano offered many advantages to the early inhabitants of the place, but without granting them civic rights, privileges or any form of ownership.
In fact, the peasants could reside in the forest but with an express prohibition on building homes using any type of lime, according to the law known as the "Pragmatic ‘De Baronibus’", that forbade build houses without authorization. To get around this prohibition the houses known as "casedde" ("small houses") were built without the use of lime, thus "stone by stone", ready to be torn down for an inspection.
Early history of Alberobello
The history of Alberobello dates back to the 11th century, when a wood called "Sylva aut nemus arboris belli" ("Forest or Wood of the tree war") was donated to the Bishop of Monopoli.
This can be seen in documents of King Robert of Anjou (1277-1343, who reigned from 1309 to 1343), where it was said that this forest was donated to the municipality of Martina Franca. At that time it was a fief of the Acquaviva family, the Counts of Conversano, in particular falling under Girolamo II Acquaviva, called the “Guercio di Puglia” (1626-1665).
Despite the prohibition on building houses using lime to 'cement' the stone together, the forest was also inhabited thanks to concessions by the Count of Conversano, that in 1609, and following a request from a group of families, erected the first chapel-shrine, to give the inhabitants the opportunity to honour the cult of religion to which the settlers were fervently devoted.
Of great importance to the development of the very first Alberobello was the Count Gian Girolamo II Acquaviva, called “Guercio di Puglia”. He more than any other contributed to the increase of the so-called "casedde" houses and of the population.
The concessions of Guercio di Puglia, the consequent enlargement of the forest and its vital development, attracted the interests of all his feudal neighbour lords, who formed an alliance in asking the King to regulate the development of the forest and respect of the Pragmatic law. Subsequently, and in preparation for the inspection, the Count demolished in a single night all the “casedde” and then rebuild them immediately after the visit of the Royal Inspector.
From the 18th century, however, things changed radically, and the inhabitants of Alberobello gained from King Ferdinand IV (1751-1825) the privilege to be able to build their houses, and in this way the city lost its feudal servitude, becoming a Royal City.
Where did the name Alberobello come from?
As regard the etymology of the name, there is agreement among scholars who derive the Alberobello name from "Sylva arboris belli", to recall a forest of Oaks trees in the place, and in particular a secular tree called the "arbor belli", or "tree of war". 
The meaning of the "arbor belli" name, the "tree of war", was well explained in the“Annali della facoltà di Agraria” ["Annals of Faculty of agriculture"] as an "Apple of discord", to indicate that there was a degree of contention among various feudatories.
'Alberobello' was thus born as an "Apple of discord" between the Counts of Conversano and the Duchy of Martina; each of the contenders had a goal of increasing their revenue, colonising the fertile Alberobello soil, and inserting peasants there to act as subjects .
See also Alberobello for details of a visit to the town.
1. (See L. Binni-G. Bergamaschi, "Art in Italy", Electa, 1983:. 18.
2. see "the Annals of Faculty of Agriculture", vol. 12, Laterza, 1958: 350