John IV was the mostly absentee duke of Naples from 997 to after 1002. He was the son and successor of Sergius III. John IV originally recognised the suzerainty of the Byzantine Emperor. The dukes of Naples were the military commanders of the ducatus Neapolitanus, a Byzantine outpost in Italy, one of the few remaining after the coming of the Lombards and Saracens. ... Events City of Gdansk is founded Saint Adalbert of Prague is sent to Prussia by Boleslaus I of Poland Samuil of Bulgaria crowned Tsar by Pope Gregory V The town of Trondheim is founded. ... Events November 13 - English king Ethelred gives order to kill all Danes in England, leading to the St. ... This is a list of Byzantine Emperors. ...

In 999, he was captured and taken a prisoner first to Capua, then back to Germany by Otto III, the Holy Roman Emperor, who had just visited Saint Nilus the Younger in Gaeta. During his absence, Naples seems to have continued in allegiance to the Greeks, though it was technically governed by Adhemar of Spoleto. In 1002, John reappears in his duchy, probably released by Otto's successor, Henry II. Capua is a city in the province of Caserta, (Campania, Italy) situated 25 km (16 mi) north of Napoli, on the northeastern edge of the Campanian plain. ... The Holy Roman Emperor was, with some variation, the ruler of the Holy Roman Empire, the predecessor of modern Germany, during its existence from the 10th century until its collapse in 1806. ... Nilus the Younger of Rossano, in Calabria; born in 910, died 27 December 1005. ... Gaeta (ancient Latin name Caieta) is a city in Province of Latina, in Lazio, Italy. ... Henry II with his wife Cunigunde of Luxemburg Saint Henry II (972 – 13 July 1024), called the Holy or the Saint, was the fifth and last Holy Roman Emperor of the Saxon or Ottonian dynasty. ...

John had one son, Sergius, who succeeded him, and two daughter. The elder was Sichelgaita (whose name may imply that John had a Lombard wife), who married John IV of Gaeta and thus cemented alliance between her brother and Duke John V of Gaeta. A second daughter is recorded unnamed by Amatus of Montecassino as having been widowed by the count of Gaeta and remarrying soon after to Ranulf Drengot, the Norman count of Aversa. This latter account is confusing, but not impossible. Sergius IV (d. ... The Lombards (Latin Langobardi, whence the alternative name Longobards found in older English texts), were a Germanic people originally from Northern Europe that entered the late Roman Empire. ... Amatus of Montecassino (Amatus Casinensis), a Benedictine monk at the Abbey of Montecassino is one of three Italo-Norman chroniclers, the others being William of Apulia and Goffredo Malaterra. ... Rainulf Drengot (also Ranulph, Ranulf, or Rannulf) was a Norman adventurer and the first count of Aversa (1030–1045). ... Norman conquests in red. ...

Sources

• Chalandon, Ferdinand. Histoire de la domination normande en Italie et en Sicilie. Paris, 1907.