Landulf IV (died 13 July 982) was the prince of Capua (as Landulf VI) and Benevento from 968, when he was associated with his father, Pandulf Ironhead, and prince of Salerno associated with his father from 977 or 978. In 968, his uncle Landulf III died and this was the occasion of his rise, as Pandulf ignored the rights of Landulf's son Pandulf, his nephew, and instead associated his own son with the government.
In 969, the Ironhead was captured in the Battle of Bovino. The strategos of Bari, Eugenius, captured the town of Avellino and besieged Capua, then Benevento. Landulf's mother, Aloara of Capua and Landulf I, Archbishop of Benevento, took over the government in his name, to defend the city from the Byzantines. In 977, after the Ironhead's release, he joined his father in an expedition in defence of Monte Cassino against the predations of Count Bernard of Alife.
On Pandulf's death in March 981, the great Lombard principality was divided: Landulf, the eldest son, received Capua-Benevento and Spoleto, and Pandulf, the second son, received Salerno. However, the Emperor Otto II, who was in the Mezzogiorno at the time, fighting the Saracens, dispossessed Landulf of the duchy of Spoleto and gave it to Thrasimund, duke of Camerino and count of Penne. Soon thereafter, Landulf was forced also to recognise the division of Capua-Benevento, united since 899. His cousin, the aforementioned deprived Pandulf, as prince of Benevento, perhaps as an underling. Thereafter, Landulf was merely prince of Capua, in which capacity he supported the Cluniac reform and founded the church of San Croce at Caiazzo. He joined his deposed brother Pandulf in Calabria, where they fought the Saracens with Otto. They both died in the Battle of Stilo on 13 July. He was succeeded by his younger brother Landenulf, who was under the regency of Aloara.
- Caravale, Mario (ed). Dizionario Biografico degli Italiani: LXIII Labroca – Laterza. Rome, 2004.
| Prince of Capua
| Prince of Benevento
| Duke of Spoleto