When Charlemagne entrusted the pieve of Gropina to the powerful monastery of Nonantola, this opened a new period of splendour which lasted well past the 10
th century. Then its direct dependence on Nonantola ended and the great process of reconstruction of religious buildings after the year 1000 included the pieve of Gropina. Having overcome the terror of the Apocalypse, all of Europe had a passion for building, also as a result of the considerable increase of agricultural production and consequently of the population. "It was as if the world itself, shaking off and freeing itself from all that was old, covered itself in a white mantel of churches", wrote Rodulfus Glaber (c. 980/85-c. 1047/50) in a famous passage from his Chronicles of the Year 1000 (III, 13, 19). Before the new millennium (9th-10th century) the phenomenon of encastellation, creating walled towns to protect their citizens in the wake of the new wave of Saracen, Hungarian and Norman invasions, was destroying the Carolingian empire and the feudal system founded by Charlemagne. According to Mons. Angelo Tafi (1989), fortification was one of the reasons for profound social and political renovation in the Valdarno, along with the resulting birth of communities and the presence in the zone of mendicant orders, such as the Franciscans, who occupied themselves with spiritual matters independently. All of these led to a partial repartitioning of the territory of the pievi among the parish churches around the 12th century, and consequently the transfer of authority for public works and the running of spedali [hospitals]. This was the case for the pievi of Gropina and of San Giustino Valdarno, another one of the six pievi built along the Cassia Vetus (today the Strada dei Setteponti), the road around which the new parish churches arose between the 12th and 13th centuries. It is precisely in this period that the pieve di San Pietro a Gropina assumed its Romanesque appearance, the result of a grandiose reconstruction which completely changed its Early Medieval aspect. It is not to be ruled out, or rather it is very probable, that the powerful feudal lords of the territory between the Arno and the Pratomagno, the counts Guidi of Romena and of Battifolle, who held Gropina and the Castle of Loro in the 13th century, participated in these vast projects.
Thus the influence of the pieve of Gropina spread over the entire diocese of Arezzo, with the constant addition of new suffragan churches, as demonstrated by the well-known
Libro di Montaperti and the Rationes Decimarum, listing churches under their respective parishes. At the beginning of the 14th century the Castle of Loro passed under the jurisdiction of the Florentine Republic, and the golden period of Gropina, which was already part of Loro since the second half of the 13th, continued. With the advent of the Medici it reached its peak in the economic sphere as well.
There are no known documentary sources on the reconstruction of the Romanesque pieve, but the stones themselves shed some light: the date “1233” in Roman numerals on the bell-tower indicates the year of its construction, or at least of its foundation, while on the architrave of the entrance door a very worn away “1422” might refer to the date of a restoration. In a letter of April 9, 1469 sent from the parish priest Samuele to Lorenzo il Magnifico, and published by Carlo Fabbri (2005), there is mention of a chapel built thanks to a bequest of Giovanni da Loro. Its first chaplain was to be a certain
ser Benedetto, "appointed by pope Eugene the first time he was in Florence". Eugene IV became pope March 11, 1431, and nine years after the date on the architrave seem too many for a chapel to have been left without its priest; therefore it is probable that the year 1422 referred to so-far undocumented works, and not to the ones mentioned in the testament of messer Giovanni da Loro.
Almost two decades after the letter of the parish priest Samuele, Lorenzo il Magnifico again took interest in the pieve di Gropina: this time it was to recommend its assignation to the court poet Agnolo Poliziano, who was also an ecclesiastic. Lorenzo ordered his ambassador to Rome, Giovanni Lanfredini, to go to the pope to ask – obviously as politely and reverentially as possible – for Poliziano to be effectively made beneficiary of the pieve di Gropina with all of its land, since the endowment had already been made, but only on paper. The letter is dated March 22, 1487 Florentine style (i.e. 1488 because in Florence the year began on March 25, day of the Incarnation). That pope was Innocent VIII, who shortly before that had condemned the nine hundred propositions pf Pico della Mirandola, another intellectual close to Lorenzo il Magnifico. Nevertheless, Agnolo Poliziano did receive his benefice. The pieve of Gropina carries yet another record of Lorenzo and also of his son Giovanni, cardinal and then Pope Leo X, who assigned it to the Florentine Church in 1522. The interest of the Medici reveals the religious and economic importance of the pieve between and 14
th and 15th centuries; moreover, the qualities of the wine and oil produced on its land has been appreciated and celebrated for centuries, even by celebrities such as Benvenuto Cellini... The patronage of the Medici over the pieve di Gropina is the jewel in the crown of this marvelous church, which can even boast of the intervention of a pope. In the following centuries Gropina followed the destiny of Loro (which added to its name that of the stream Ciuffenna in 1862), from the birth of the principality with the Medici Grand Dukes to the occupation by Napoleon and the following restoration, in 1815, of thel Grand Dukedom of Tuscany, up to the proclamation of the unity of Italy.
An important project of works on the pieve was undertaken in the years 1968-1971, with the discovery of the Roman, Paleochristian and Lombard remains, which have enabled us to unravel the thread of its story from antiquity – from when history itself is mixed with legend and with the ancient rumours of a temple dedicated to Diana, between the woods and springs, where the pieve is today and once upon a time there lived the Goddess.