Sico II was the first prince of Salerno. Son and successor of Siconulf, he reigned from his father's death in 851 to his deposition

Deposition (politics)

Deposition by political means concerns the removal of a politician or monarch. It may be done by coup, impeachment, invasion or forced abdication...

 in 853. He is given the ordinal "II" because he was the second Sico to rule in the south, the previous Sico

Sico of Benevento

Sico was the Lombard Prince of Benevento from the 817 to his own death.-Life:Before becoming the Prince of Benevento, he had been the gastald of Acerenza. On the assassination of Grimoald IV, Sico succeeded to the princely throne...

 being prince of Benevento.

Sico was a minor when his father died and was put under the tutelage

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 Peter

Peter of Salerno

Peter was originally the tutor and guardian of the young prince of Salerno, Sico II. He held that post for two years from 851 to 853....

. Peter deposed him and he fled north to the Emperor Louis II. According to the Chronicon Salernitanum

Chronicon Salernitanum

The Chronicon Salernitanum, or "Salerno Chronicle", is an anonymous 10th century chronicle of the history of the Principality of Salerno. It was probably written around 990 and has been attributed to Radoald of Salerno, Abbot of San Benedetto, by Huguette Taviani-Carozzi...

, he eventually came of age in 855 and returned to claim his principality but was poisoned.