Gisulf I (May 930 – November or December 977) was the eldest son of his father, Guaimar II

Guaimar II of Salerno

Guaimar II was the Lombard prince of Salerno from 901, when his father retired to a monastery, to his death. His father was Guaimar I and his mother was Itta. He was associated with his father in the principality from 893...

, and his second wife Gaitelgrima

Gaitelgrima

Gaitelgrima is a Lombard feminine name. There are several notable Gaitelgrimas in history. The identities of these four women are often confused because they were all closely related to each other and to two men: Guaimar III of Salerno and his son, Guaimar IV, whose enumeration is often altered...

. He was associated with his father as prince of Salerno in 943 and he succeeded him on his death in 952. He took to using the title Langobardorum gentis princeps: "prince of the people of the Lombards." He was originally under the regency

Regent

A regent, from the Latin regens "one who reigns", is a person selected to act as head of state because the ruler is a minor, not present, or debilitated. Currently there are only two ruling Regencies in the world, sovereign Liechtenstein and the Malaysian constitutive state of Terengganu...

 of his mother and Prisco (Priscus), treasurer (comes tesaurarium) and count of the palace (magister palatii).

In 946, he was assaulted by an alliance of Landulf II of Benevento

Landulf II of Benevento

Landulf II , called the Red, was the Lombard prince of Benevento and prince of Capua from 939 or 940, when his father, Landulf I, first associated him with the government, his mother was Gemma, daughter of Athanasius of Naples. He may have been associated as early as 933, when his elder brother,...

 and John III of Naples

John III of Naples

John III was the longest-reigning Duke of Naples . He was the son and successor of Marinus I.At the beginning of his reign, he warred against the Saracens and then made a treaty with them after they appeared beneath his walls in 929...

, but his own ally, Mastalo I of Amalfi, came to his rescue and ambushed Landulf's forces at La Cava

Cava de' Tirreni

Cava de’ Tirreni is a city and comune in the region of Campania, Italy, in the province of Salerno, 10 km northwest of the town of Salerno...

. In the next year, he allied with Landulf and besieged Neapolitan Nola

Nola

Nola is a city and comune of Campania, southern Italy, in the province of Naples, situated in the plain between Mount Vesuvius and the Apennines...

. In October 953, he issued a diploma favouring the bishop of Naples, but the unscrupulous diplomacy of his neighbours never seemed to favour him. Sometime after 955, however, he was made a patrician by Marianus Argyrus, 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...

of Bari

Bari

Bari is the capital city of the province of Bari and of the Apulia region, on the Adriatic Sea, in Italy. It is the second most important economic centre of mainland Southern Italy after Naples, and is well known as a port and university city, as well as the city of Saint Nicholas...

. In Autumn 966, Pope John XIII

Pope John XIII

Pope John XIII of Crescenzi family served as Pope from October 1, 965, until his death.Born in Rome, he spent his career in the papal court...

 led a Roman-Tuscan-Spoletan army against Landulf III of Benevento

Landulf III of Benevento

Landulf III was Prince of Capua and Benevento from 959 as co-prince with his father, Landulf II and brother Pandulf Ironhead, and from 961 only with his brother. His mother was Yvantia....

 and his brother Pandulf Ironhead

Pandulf Ironhead

Pandulf I Ironhead was the Prince of Benevento and Capua from 943 until his death. He was made Duke of Spoleto and Camerino in 967 and succeeded as Prince of Salerno in 977 or 978...

, but Gisulf came to his rescue and no battle was given. The pope and Gisulf made a treaty at Terracina

Terracina

Terracina is a town and comune of the province of Latina - , Italy, 76 km SE of Rome by rail .-Ancient times:...

. It was this act which bought him later assistance from the powerful Ironhead.

In 973, Gisulf was deposed and removed from office by Landulf of Conza

Landulf of Conza

Landulf of Conza , a Lombard nobleman, was briefly Prince of Benevento in 940 and then briefly Prince of Salerno in 973. The son of Atenulf II of Benevento, Landulf ruled on his father's death as co-prince with his uncle, Landulf I, who soon sent him into exile...

 and his sons in alliance with Marinus II of Naples

Marinus II of Naples

Marinus II was the Duke of Naples from 968 to his death. He was the son and successor of John III and brought Naples back into the Byzantine fold, receiving the title eminentissimus consul et dux, atque imperialis anthipatus patricius. In 970, Marinus did homage for his duchy to the patrician...

 and Manso of Amalfi. His neighbour, the prince of Benevento and Capua, Pandulf Ironhead, restored Gisulf as his vassal. Though Gisulf was married to Gemma, he died heirless in late 977 (or perhaps 978) and Pandulf succeeded in Salerno.