Gregory IV was the firstborn son of Duke Sergius II of Naples

Sergius II of Naples

Sergius II was Duke of Naples from 870 to 877.He continued the policies of his father, Gregory III, and grandfather, Sergius I. He maintained good relations with the Franks or the Byzantines only as it suited Neapolitan interests....

 and successor of his paternal uncle, Bishop Athanasius

Athanasius of Naples

Athanasius was the Bishop and Duke of Naples from 878 to his death. He was the son of Gregory III and brother of Sergius II, whom he blinded and deposed in order to seize the throne while he was already bishop....

, in 898, when he was elected dux, or magister militum

Magister militum

Magister militum was a top-level military command used in the later Roman Empire, dating from the reign of Constantine. Used alone, the term referred to the senior military officer of the Empire...

, unanimously by the aristocracy. His other paternal uncle, Stephen, succeeded Athanasius as bishop

Roman Catholic Archdiocese of Naples

The Roman Catholic Archdiocese of Naples is a Roman Catholic ecclesiastical territory in southern Italy, the see being in Naples. A Christian community was founded in the 1st century AD and the diocese was raised to the level of an Archdiocese in the 10th century. Two of Archbishops of Naples have...

. According to the Chronicon ducum et principum Beneventi, Salerni, et Capuae et ducum Neapolis, he reigned for sixteen years and eight months.

The Mezzogiorno

Mezzogiorno

The Midday is a wide definition, without any administrative usage, used to indicate the southern half of the Italian state, encompassing the southern section of the continental Italian Peninsula and the two major islands of Sicily and Sardinia, in addition to a large number of minor islands...

 in his time was under constant Saracen

Saracen

Saracen was a term used by the ancient Romans to refer to a people who lived in desert areas in and around the Roman province of Arabia, and who were distinguished from Arabs. In Europe during the Middle Ages the term was expanded to include Arabs, and then all who professed the religion of Islam...

 assaults. Around 900, Gregoy destroyed the castrum Lucullanum, a Neapolitan fortress just outside the city, to prevent the Moslems from taking it as a base. Otherwise, he reinforced the city walls and stored supplies to ensure survival in the event of a long siege. According the much later chronicler Leo of Ostia

Leo of Ostia

Leo Marsicanus or Ostiensis , also known as Leone dei Conti di Marsi , was a nobleman and monk of Monte Cassino around 1061 and Italian cardinal from the twelfth century.In Monte Cassino, he became a friend of Desiderius of Benevento, later Pope Victor III, and it was to him that Leo dedicated...

, he signed a pact with the prince of Benevento and Capua, Atenulf

Atenulf I of Capua

Atenulf I , called the Great , was the prince of Capua from 7 January 887 and of Benevento from 899, when he conquered that principality...

, and the Amalfi

Amalfi

Amalfi is a town and comune in the province of Salerno, in the region of Campania, Italy, on the Gulf of Salerno, c. 35 km southeast of Naples. It lies at the mouth of a deep ravine, at the foot of Monte Cerreto , surrounded by dramatic cliffs and coastal scenery...

tans and attacked and defeated the Saracens. On 2 July 911, he signed another pactum with Atenulf's sons, the coprinces Atenulf II and Landulf I

Landulf I of Benevento

Landulf I , sometimes called Antipater, was a Lombard nobleman and the Prince of Benevento and of Capua from 12 January 901, when his father, Atenulf I, prince of Capua and conqueror of Benevento, associated his with him in power...

, whereby they shared the disputed territory of Liburia.

In that same year, he participated in allied attacks on the Saracen fortress on the Garigliano. In 915, he joined the massive army of south Italian princes and the Byzantine

Byzantine Empire

The Byzantine Empire was the Eastern Roman Empire during the periods of Late Antiquity and the Middle Ages, centred on the capital of Constantinople. Known simply as the Roman Empire or Romania to its inhabitants and neighbours, the Empire was the direct continuation of the Ancient Roman State...

 strategos

Strategos

Strategos, plural strategoi, is used in Greek to mean "general". In the Hellenistic and Byzantine Empires the term was also used to describe a military governor...

Nicolaus Picingli and received the imperial title of patricius. The army met with the forces of the central peninsula under Alberic I of Spoleto

Alberic I of Spoleto

Alberic I was the Lombard duke of Spoleto from between 896 and 900 until 920, 922, or thereabouts. He first appears as a page to Guy III of Spoleto at the Battle on the Trebbia in 889 He may have later been the count of Fermo or margrave of Camerino, but whatever the case, he succeeded to Spoleto...

 and Pope John X

Pope John X

Pope John X, Pope from March 914 to May 928, was deacon at Bologna when he attracted the attention of Theodora, the wife of Theophylact, Count of Tusculum, the most powerful noble in Rome, through whose influence he was elevated first to the see of Bologna and then to the archbishopric of...

. Together they led another assault on the encampment of the Garigliano. In the ensuing battle

Battle of Garigliano

The Battle of Garigliano was fought in 915 between the forces of the Christian League and the Saracens. Pope John X personally led the Christian forces into battle.-Background:...

, it was on the misplaced (or mendacious) advice of Gregory that they charged the Saracen line. Nevertheless, it was a success and the enemy fled into the forest to be hunted down and slaughtered. Gregory did not long live to enjoy the fruits of victory, he died within months, late in the year 915, and was succeeded by his firstborn son, John II

John II of Naples

John II was the duke of Naples from 915 to his death. He succeeded his father Gregory IV on the latter's death late in 915.He had accompanied his father to the Battle of the Garigliano under Nicholas Picingli, where the Christian coalition defeated the Moslems of the fortress on the Garigliano....

, who had been present at the battle.

In 907 Gregory made a donation to the urban church of Saints Severinus and Sossus in Naples, which his forefathers had possibly founded.

Sources

• Caravale, Mario (ed). Dizionario Biografico degli Italiani: LIX Graziando – Grossi Gondi. Rome
  Rome
  Rome is the capital of Italy and the country's largest and most populated city and comune, with over 2.7 million residents in . The city is located in the central-western portion of the Italian Peninsula, on the Tiber River within the Lazio region of Italy.Rome's history spans two and a half...
  
  , 2002.