In southern Italy, the Normans had to cope with a very varied ethno-cultural and religious situation due to the coexistence in the region of Latins, Lombards, Greeks, Arabs and Jews. In the first place (under Robert Guiscard and Roger I), the policy of the leading Norman lords with regard to the Church fell into line with the directives of the Gregorian reform, and they took an anti-imperial stance. Later on, with the institution of the monarchy, the kings tightened their grip on both the Greek and Latin churches, while their relationship with the pope was exclusively political.
As regards the organisation of the Church in southern Italy, during the Norman period the number of dioceses multiplied, so that the individual bishops had less political power. On the other hand, monasticism developed notably in the Norman period, when numerous Greek and Latin monasteries were founded in Sicily and new foundations were made by the Norman leaders on the mainland. However, none of the orders of French origin were present in this region. In the 12th century small local orders were founded, but only in some of the most northerly areas of the kingdom (Irpinia, Sannio and Capitanata).
Generally speaking, during the early Middle Ages - after the war between the Greeks and the Goths, and the Lombard invasion - the Church ceased to function as an organized body. The few surviving bishops were often responsible for vast dioceses (as was that of Benevento for a long period). Furthermore, in the area under Byzantine domination, the eastern emperors had created a series of metropolises adhering to the Greek rite. However, during the 11th century, other bishops took over the pastoral charge of the Greek minorities in the Latin areas, both in Taranto and in the principality of Salerno. The response of the papacy was, from the late 10th century onwards, the creation of a series of metropolitan archbishoprics: Capua, Benevento, Naples, Amalfi and Salerno.
The situation in Sicily was much more radical. The island had experienced neither the Lombard invasion nor the collapse of the towns, but the Arab invasion had swept away the ecclesiastical institutions and, when the Normans arrived they found only two bishops on the island. In fact, they - especially Roger I - were responsible for reconstructing the Church in Sicily
The Normans had to contend with a situation that was very complex and problematic. In the early stages of the conquest the number of cities seeking to acquire bishoprics increased rapidly (they even included small towns such as Mottola, Castellaneta, Bitonto and Bitetto). Moreover, some sees, such as Aversa and Melfi, did not form part of the metropolitan network and were directly under Rome. In the 12th century the Norman kingdom possessed no less than 150 dioceses, some of them extremely small indeed. This meant that, generally speaking, bishops in southern Italy carried little weight and had very limited resources.
The appointments depended on three factors: the local forces, political power and the papacy. The reformist popes of the 11th century came to an agreement with the Norman lords (council of Melfi, 1059); later on, the conferral by Urban II in 1098 of the so-called legantine commission over Calabria and Sicily on Roger I was of decisive importance. The pope’s relations with the monarchy were not so good: besides Anacletus II’s schism (1130-38), supported by Roger II, in 1156 William I imposed the treaty of Benevento on Pope Adrian IV. This strictly regulated the intervention of the pope in the kingdom and gave the king the right of veto on the appointment of bishops.
The lack of a normal network of bishoprics left considerable room for the private church, which for a long period had a virtual monopoly of the pastoral organisation. The transition from the private church to the parish church as the basic structure of the pastoral organisation appears to have taken place as a result of the Norman unification in the 12th century.
The private church was an early medieval institution; founded by private individuals, its churches reserved the right to appoint the officiants. Thus the bishops were accustomed to underwriting release documents, in which they waived any material rights over the private churches and their clergy. The situation began to change in the 11th century to meet the new requirements of the Church of Rome and also as a result of the Norman Conquest. At the end of the following century, the very principle of the private church was called into question. Hence the parish church began to perform a wide range of pastoral functions: baptisms, funerals, benedictions - although some monastic churches also obtained these rights.
The problem of the celibacy of priests existed in southern Italy, as it did elsewhere. The sources mentioned numerous priests, married or otherwise, with offspring. It appears that the region was tardy in its evolution towards celibacy: one of the fundamental institutions of the period of the reform that of the canons regular, which exalted celibacy and the communal life of the clergy, was poorly represented. There were also few secular canons before the multiplication of the cathedrals (they existed at Santa Maria di Bagnara, in Calabria, and at the collegiate church of San Pietro ad Aram, in Naples). Often, in addition to the religious life, priests engaged in the professions - for instance, that of notary. The lower orders of the priesthood were recruited from all social strata, while the important offices were held by members of the aristocracy.
Monasticism under the Normans
Numerous Greek monastic communities were founded in Norman southern Italy, while the great currents of renewal in Western monasticism in the 10th and 11th centuries only reached the region indirectly and were limited to certain parts of it.
Monasticism following the Greek rite mainly regarded Sicily, Calabria and southern Lucania (Melicuccà, founded by St Elias the Speleote; San Peter Imperialis in Taranto, etc.). The most famous of the hermit founders of monasteries, St Nilus the Younger, settled in Campania and then near Rome. From the 11th century onwards, the Greek monastic foundations observed the rules of St Basil the Great and St Theodore Studites (eastern monasticism did not have a single rule, such as the Benedictine one in the West).
The attitude of the Normans towards the Greek monasteries was far from being hostile. Some Greek monasteries were placed under the control of Latin abbeys - for instance, St Peter Imperialis in Taranto, which came under Montecassino. However, in the Greek-speaking area new monasteries were founded, especially in Calabria and Sicily during Roger I’s reign, and in the Salento peninsula under Bohemond of Antioch. Thus Greek monasticism did not lose its vitality in the Norman period, but the civil authorities confined it to specific areas and helped to give it a structure similar to that of Benedictine monasticism.
The leading Benedictine monastery in early medieval southern Italy was Montecassino; other important ones were St Sophia in Benevento, St Vincent on Volturno, St Clement of Casauria (in the Abruzzi) and Holy Trinity of Cava. These large monasteries had dependencies and held land in other areas of southern Italy.
The Norman era brought innovations for which the conquerors were not responsible. However, they did favour the immigration, from Normandy, of monks, whom they appointed as abbots of monasteries. St Lawrence in Aversa was entrusted to Robert of La Croix-Saint-Leufroy in Normandy; Robert Guiscard revived many houses, transferring monks from Saint-Évroult-sur-Ouche to them, especially the famous Robert of Grandmesnil (they included Holy Trinity of Venosa, St Mary of Sant’Eufemia, Holy Trinity of Mileto, etc.).
In the Norman period, moreover, the pre-existing monastic foundations also developed. Montecassino enjoyed its period of greatest splendour in the late 11th and early 12th centuries with the abbots Desiderius and Oderisius, while the expansion of Cava continued during the 12th century. The latter abbey received donations from all over mainland southern Italy and was given the task of sending monks to the royal foundation at Monreale.
Numerous forms of monastic spirituality flourished from the 10th to the 12th centuries; these were mainly associated with the French abbeys of Cluny (Cluniac monasticism) and Cîteaux (Cistercian monasticism). In addition, there was a rebirth of hermitism: the Camaldolese founded by St Romuald and the Carthusians founded by St Bruno. These developments did not have a strong impact on Norman southern Italy. This applied especially to the Carthusians, although St Bruno died in Calabria in 1101. The influence of the Cistercians was a little greater (Santa Maria del Saggitario, in Lucania, Santa Maria de Ferraria, near Teano). The two main promoters of the new monasticism were St John of Matera (d. 1139), founder of the monastery of Pulsano, on the Gargano and St William of Vercelli (d. 1142) founder of Santa Maria di Montevergine (near Avellino).
The Salernitan Alferius, who, while on a mission to France, had encountered the abbot of Cluny, Odilo, founded the abbey of the Holy Trinity of Cava in Campania in 1025. The Joachimite movement is another story: it was founded by the Calabrian Cistercian monk Joachim of Fiore about 1190 at San Giovanni da Fiore, in the Sila Mountains.
 Salvatore Fodale ‘L’Église et les Normands en Italie du Sud et en Sicile’, Les Normands en Méditerraneé, University of Caen, 1994, pages 171-178.
 Errico Cuozzo ‘Les évêques d’origine normande en Italie et en Sicile’, Les évêques normands du XIe siècle, University of Caen, 1995, pages 67-78 has some useful things to say.