Castelnuovo takes its name from the ancient Roman"Castrum Camajani" , in fact at the times of imperial Rome it was a military place,a rather important fortress. Little by little a new village sprang up on the ruins of the ancient "Castrum", and around them, therefore it took the name of new "castrum", or Castelnuovo.
Later the Charity House of Mercy of Pisa got large possessions here, given by the Gherardesca earls, therefore Castelnuovo was called "of Mercy", in order to distinguish it from many other villages of the same name. The Charity House of Mercy is still recognized as "direct property" of many lands given as surveyor's level.
Camajano is first mentioned in a level document which dates back to 857, that is 1148 years ago.
However some marble memorial stones, discovered long time ago where the castle is situated ,are evidence of the presence of the Etruscans in these places..
In 1040 at Camajano Sismondo di Cunitto and other noble Pisans drew up a notarial deed to sell a villa and some lands near the castle of Vada.
In 1126 the archbishop of Pisa, Uberto of the Lanfranchi, donated to the chapter of the Pisan Primazial Church his part of ownership of the Camajano castle and of the Popogna one. In a will Guido daFasciano, son of the late Ranuccio, declares he will leave his possessions to the hospital of St. Lorenzo di Stagno if he dies heirless. Among these possessions there are Colle and Castelvecchio in Faldo. The will dates back to May,28th 1182.
In different periods some memorial stones cippi, sepulchral inscriptions of the roman period ,,small mileposts, etc.were unearthed in Castelnuovo.
On the Rialdo ditch you can still see the ruins called "the Pievaccia" that refer to the ancient S. Giovanni churh, while the present parish church is dedicated to St. Stefano and was erected from1638 to1642 and restored in 1842.
The rests of the ancient church of St.Stefano are inserted in the southern part of the castle, to the left of the entrance door, in a private building. Before 1776 Castelnuovo was a municipality itself , after the law of the 27th of June 1776 about the new municipality regulations,the municipality of Castelnuovo, which in previous times was called municipality of Colle , was united to the one of Rosignano and actually, according to the mentioned law, the first gonfalonier to be elected was an inhabitant of Castelnuovo, Mrs Giuseppa di Domenico Cantalupi who charged the priest of Rosignano, father Marco Salvetti, with the execution of her duties.
According to the law of 1776 women could both elect and to be elected. Later the Municipality of Rosignano had other two inhabitants of Castelnuovo as heads : Mr Francesco Lobin, Gonfalonier in 1842 and Mr. Giuseppe Comparini , Mayor in 1909.
On The 30th September 1786 Dr Leopoldo Benci of Castelnuovo was appointed first municipal doctor.In 1787 Castelnuovo had the first schoolteacher.
On April 16th 1796 the edict for the construction of the tank on the land of the noble Bernardi was published . The tank was built by the master mason Iacopo Geri, while the engineer Giovanni Andreini was the director of the jobs. The tank cost 860 scudos and its capacity is of 6,000 barrels. It is remembered that in 1837, according to the laws in force, a landowner of Castelnuovo named Pardini Cosimo was exonerated from taxes because he was the father of 12 living children.
In 1848 the rural postman between Rosignano and Castelnuovo was instituted with three journeys a week.
In 1866 the first girls' school was instituted at Castelnuovo and in 1868 the fair was fixed on the Monday after the third Sunday of October.
The population of Castelnuovo,very hard-working and industrious,thanks to several ethnic characteristics,seems to be the continuation of an ancient colony, perhaps roman.
The present aspect of the village is outlined by a considerable construction which has developed during the latest decades.
Anyway there remain the two most important historical settlements : Castelnuovo and Castelvecchio. Thanks to their geographical position and strategic military importance, most of all between the 12th and 17th centuries, they dominated over the plain below and the important Maremma street, (today S.S.206), that in the past has been the only possible way between Pisa in the north and Maremma in the south.Castelnuovo has a middle height of 165m,it's at a distance from the sea km 4.3.The population is about 1400 residents.