An important change in the status of the Norman mercenaries occurred after 1040. After the expedition to Sicily tensions rose between the former allies. In 1041, the Lombard cities of Apulia revolted against Byzantine control led by the Lombard Argyrus, Melus’ son and by Arduin, the leader of the Sicilian expedition in 1038. Arduin was the official administrator of the Melfi area on behalf of the Greek Empire. He attempted to make a place for himself in the region with the help of his former Norman comrades-in-arms, the Hauteville brothers and in March 1041 he and his allies seized Melfi and launched a new invasion of Apulia.
The rebels took advantage of the death of the catepan Nikephorus Dokeianos, who had died at Ascoli in January 1040 and the leaderless province was then struck by a revolt in the Taranto region in May and by the seizure of Bari by Argyrus soon after. The rebels inflicted two severe defeats on the Byzantine army in 1041: the catepan Michael Dokeianos and a hastily assembled Greek army was defeated on 17th March in a battle fought beside the River Olivento between Melfi and Lavello; seven weeks later on 4th May the Normans defeated a much larger Greek army at Canne, not far from the coastal town of Barletta. The Byzantines now only controlled the southern part of Apulia but the rebel campaign appears to have stalled and both sides devoted the summer of 1041 to building up their strength.
The Greeks transferred troops from Sicily and Calabria; Michael Dokeianos was replaced as catepan by the son of the former governor Basil Boiannes. Their opponents sought local allies. Arduin enlisted the support of Rainulf of Aversa and Adenulf of Benevento was ‘elected’ (he almost certainly used bribes) to become leader of the Normans. The campaign began again in September 1041 with the Normans routing a Byzantine army near Montepeloso (modern-day Irsina) on the River Bradano and capturing the catepan. As a result, all the coastal towns abandoned Byzantium and threw their lot in with the Normans. However, conflict between the Normans and prince Atenulf of Benevento over ransoming prisoners taken at Montepeloso, the Normans elected Argyrus was elected their leader in Bari in February 1042.
The Byzantines were also affected by internal divisions. The death of the Emperor Michael IV in December and the accession of his nephew Michael V led to the return to favour of George Maniakes who returned to mainland Italy with orders to crush the Lombard rebellion in Apulia. The former prince of Capua, Pandulf IV was allowed to return to Italy presumably to destabilise the Lombard principalities. Maniakes arrived at Taranto in April 1042 regaining the towns that had thrown off Byzantine rule with some brutality but refused a pitched battle with Argyrus and the Normans.
The Emperor Michael V proved unpopular and was deposed in April 1042. This placed Maniakes in a difficult position as he was disliked by the new emperor Constantine IX. Maniakes soon after declared himself emperor and began preparations for an expedition to Constantinople. At the height of this confusion, in August 1042, Argyrus was bribed to return to the imperial side and he abandoned his Norman allies and retired to Bari. Whatever the Byzantine bribes, Argyrus’ decision was also motivated by a realisation that the Normans were potentially more of a threat to the coastal towns than were the Byzantines. The emperor was prepared to give these towns a considerable degree of autonomy and consequently especially Bari and Brindisi remained attached to Byzantium and opposed to the Normans.
Taking advantage of this climate of permanent anarchy, the Normans seized Melfi and the whole area to the west of Apulia, from the Ofanto valley to Matera in Basilicate. In September 1042, William of Hauteville, known as Iron-Arm and the other leaders turned to Guaimar IV of Salerno (now known as the duke of Apulia and Calabria), in order to obtain, by paying homage of vassalage to him, official recognition of their conquests. Concerned to thwart the expansionist attempts of the Norman Rainulf of Aversa, Guaimar accepted. In 1043, the Normans in Melfi placed themselves under the authority of the prince of Salerno and divided the conquered or to be conquered country into twelve counties with a Norman in charge of each. William of Hauteville, who had become a count in 1042 and had married the duke of Salerno’s niece, held a predominant position. The fiefs were divided according to merit and rank: Ascoli for William, Venosa for Drogo etc. Melfi, the common capital where they each had a palace and control of a sector, was not divided up. The day of the mercenary was ended as the Normans established their authority within their own counties though they remained, at least in theory under the suzerainty of Salerno.
Norman advances in the mid- to late-1040s were limited to the more peripheral areas. There were two main reasons for this. First, the Byzantines retained control of the larger towns of Bari, Trani, Brindisi, Taranto, Matera and Otranto. It was only the smaller settlements that fell under Norman control. Secondly, the siege of Bari in 1043 showed that the Normans had yet to develop effective siege tactics for large towns. In 1044, count William led an expedition into northern Calabria and established a base at Scribla. In 1045, Drogo captured Bovino and the Normans began to penetrate into the Capitinate. By 1045, the Normans were making incursions into the principality of Benevento and by the early 1050s much of the southern part of the principality had been secured by the Normans. However, Abbot Richer of Montecassino pursued a vigorous policy of confronting the Normans and fortifying the abbey’s lands. This combined with a degree of restraint exercised by Guaimar IV over the Normans of Aversa proved effective and the abbey lands remained largely safe from Norman attacks. In the autumn of 1042, Rainulf of Aversa, with Guaimar’s approval took over Gaeta after the Gaeteans had rejected their prince’s rule. This proved short-lived and in 1045 the citizens took advantage of Rainulf’s death to invite the Lombard count of Aquino to become their lord. His rule was unchallenged until the final take-over of the principality of Capua by the Normans in the early 1060s.
There were three important problems facing the Normans in the mid-1040s. First, there was a shortage of numbers and this make holding down captured towns and territories potentially difficult. Secondly, Norman expansion was, in part aided by divisions among the rulers of the native population: tensions between the Lombard upper class and the Byzantines in Apulia, between Pandulf IV and Guaimar of Salerno in the west and within the towns of southern Italy such as Gaeta. Thirdly, the Normans were themselves far from united. This can be seen in the comital successions after the deaths of Rainulf of Aversa in 1045 and William Iron Arm later that year.
Count Rainulf died in May 1045 and his nephew and successor Asclettin not long after. This led to a disputed succession between Rainulf, another of the old count’s nephews supported by Pandulf IV and Rodulf supported by Guaimar of Salerno. Rainulf was successful but matters were then complicated by the arrival of yet another nephew, Richard with a substantial following and some support in Aversa for his claim. Captured by Drogo, Richard was a prisoner when his cousin died and it was the influence of Guaimar than enabled his release and eventual succession as count of Aversa. However, either count Asclettin or Rainulf II had left a young son called Herman who nominally ruled Aversa between 1046 and 1050 helped by William Bellabocca, a relative of the Hautevilles. Subsequently, the Aversans expelled this William and invited Richard to become their count. This probably occurred no earlier than November 1050 and there is no further mention of the child Herman. Whether Drogo deliberately kept Richard in Apulia so his relative could act as effective ruler of Aversa is possible and certainly in the early 1050s Richard married Drogo’s sister Fressenda (perhaps as part of the agreement that secured Drogo’s consent to the succession), the period of instability in Aversa had lasted nearly six years.
The succession of Drogo who was elected in his place as overall leader of the Apulian Normans and who adopted a title that indicated the change of status of the Norman mercenaries and the ambitions of the Hautevilles: ‘duke and master of Italy, count of the Normans and the whole of Apulia and Calabria’ (‘comes Normannorum totius Apuliae et Calabriae’) was challenged by Count Peter and there appears to have been some fighting between the two factions. The Duke of Salerno gave him his daughter for a wife. Under the auspices of the Lombard project to liberate Apulia from under the yoke of the Byzantines, the Normans continued to expropriate considerable parts of the Eastern Empire’s lands.
The concession of the first Norman county, Aversa, by Sergius IV of Naples to Rainulf Drengot in 1030, and recognition of the constitution of Melfi by the Lombard Guaimar IV of Salerno to William de Hauteville in 1042, marked the end of the itinerant epoch of the Norman presence in southern Italy and the success of two families: the Drengots and especially the Hautevilles.
 Jean-Marie Martin ‘L’attitude et le role des Normands dans l’Italie méridionale Byzantine’, Les Normands en Méditerraneé, University of Caen, 1994, pages 111-122 provides some valuable comments on this issue.
 This took place in early 1043 but was short-lived and Maniakes was killed soon after he landed in the Balkans.
 On this issue see Anne-Marie Héricher-Flambard ‘Un instrument de la conquête et du pouvoir: les châteaux normands de Calabre. L’exemple de Scribla’, Les Normands en Méditerraneé, University of Caen, 1994, pages 98-110. Henri Brec ‘Les Normands constructeurs de châteaux’, Les Normands en Méditerraneé, University of Caen, 1994, pages 63-76 is more general.
 Drogo was born in Hauteville-la-Guichard, Normandy and died on August 10th 1051 at Salerno. He was the Norman count of Apulia (1046-51), half brother of the conqueror Robert Guiscard. He led the Norman conquest of southern Italy after the death of his older brother William Iron Arm, whom he succeeded as count of Apulia. Arriving in Italy about 1035 with William and his younger brother Humphrey, Drogo fought first for the Byzantines against the Muslims in Sicily, then in alliance with the Lombards in Apulia against the Byzantines. In 1042, prince Guaimar IV of Salerno made William count of Apulia and distributed the territories of Apulia among the Normans, giving Venosa, eighty miles east of Naples, to Drogo. When William died in the winter of 1045-6, Drogo succeeded him as count of Apulia, marrying Guaimar’s daughter. Drogo’s title was confirmed in 1047 by the Holy Roman emperor Henry III. He was assassinated, along with several of his followers, in an anti-Norman conspiracy as he entered the chapel of his castle at Monte Ilario to attend a mass on St. Lawrence’s Day, 1051.