The village is located not far from the prehistoric caves of Pertosa. Discovered fragments of pottery on site and a figurative Ionic vase (crater). Name of the village comes from the Roman Saint (354), who was at the court of Theodosius and then in Egypt, where he died.He had cult of greek rite. Eponym of the local church and monastery of Greek-Italian religious who had a particular reverence for the holy hermit.

His arrival is to be placed towards the end of ninth century. First settlement was on the hill (location Serrone).There is no information of the place in the Lombard period. Only in 1136 the Count of Marsico Sylvester Garner gave the church of S. Maria Maggiore to the Abbot Simeon and «totum et integrum tenimentum ecclesiesancte marie, casalis Sancti Arsenii, cum casali ipso et cum omnibus hominibus redditibus.»

The document, if authentic, is worth noting for specific concessions (pasture, trusts, forests, freedom for men to offer themselves with all their belongings to the Abbey, etc.). This had of Sant'Arsenio only the first civil and mixed jurisdiction, while the criminal jurisdiction continued to be exercised by the Counts of Marsico.
From Sylvester fiefs passed (1180) to his son William (or Goffredo?). Succeded to him William II (1163) and then Philip, which were revert goods for rebellion. Enrico Sanseverino, son of Roger (I), which had married Sica, daughter of Pandolfo Capaccio, GuaimarioIV’s brother, married Isabella Guarna, daughter of Sylvester (II) Henry obtainedto be able to buy goods before they were handed over to the IRS. He held so the county (, while his son William, then contestable and executioner, had the county of Marsico and the barony of Diano.

The church and monastery of Sant'Arsenio (priory and rectory) were confirmed to Abbot Marino and exempted from the jurisdiction of the bishop of Capaccio by Eugene III (1149) and then by Alexander III (1168). In the Archive of the Abbey of Cava there are three documents related to S.Arsenio from 1186 to 1381. The abbots of Cava were landowners of S. Arsenio for their jurisdictions between 1136 and 1513, starting from Abbot Simeon who had the donation of Silvestro (II) Guarna, Count of Marsico. Followed the abbot Marino who obtainedprivileges and other abbots, including Balsamo, Leonardo, Thomas, Americo, Leone, Bernardo, Philip de Haya, Mainerio who obtained by the bishop of Capaccio the restitution of churches of the Badia, including that of S. Arsenio. We read in the registers of this Abbot that in the period S. Arsenio remitted annually to Cava 10 golden ounces and 10 pounds of wax.

In Angevin age, for hidden fires 7, University was held to pay an ounce and tari 22 and half. Of 1366 is a letter of Queen Joanna I to the executioner of the Kingdom of Sicily for maintenanceof the assets of the hamlet of S. Arsenio and the church of St. Catherine in Polla belonging to the Abbey. In 1370 the queen asked the regent of the Curia to inquire of the raid made by the count of Marsico, Antonio of Sanseverino in the villages of St. Peter of Polla and Sant’Arsenio. On 21 June 1381 the judges Cirone Gargano of S. Arsenio and Thomas Piper of St. Peter of Polla, in their capacity as auditors representatives of the two communities lent, also on behalf of itsadministered, the oath of loyalty to the abbot Antonio, insurance of fidelity renewed on 19 May 1382.

On August 7, 1394 Boniface IX elevated as seat of dioceses Cava giving to the abbots of Cava the Episcopal jurisdiction. In the dowry was also included the Church of St. Arsenio. On August 26, 1405 King Ladislas confirmed the feud «Noble nominatim Ensenium Sancti Arsenii, pertinentiarum Dyani» to Antonio Malavolta conferred by Luigi Sanseverino with the obligationof the feudal service. In 1472 (April 17, V, S. Arsenio) was lord Sant'Arsenio Jacobello from Laurito, as we read in a scroll « De lo Laurito» concerning the sale of animals as pigs to Nicola Barile of Sant'Arsenio; followed the Cardinal Oliviero Carafa and then the monks of congregation of St. Justina of Padua later known Montecassino.First bishop of Cava and Baron of Sant'Arsenio (1513-1515) was Cardinal Luigi d'Aragona. He was succeeded by the Neapolitan Peter Sanfellice that also had the spiritual jurisdiction, civil and mixed of Sant'Arsenio.

In Cedolario we read that in 1522 S. Arsenio still owned by the monastery of Cava. The village was then given for d. 120 annual to Hannibal of Capua who becameso useful gentleman of Sant'Arsenio. The bishop Sanfelice then renounced to his title in favor of his nephew Gian Tommaso Sanfelice, who gave in perpetual lease the jurisdiction of S. Arsenio to brother Antonio or Antonello Sanfelice for 91 shields that the apostolic commissioners declared equivalent to d. 120.He sold the jurisdiction of the village to Bernardino de Hoyeda, Governor of prince Sanseverino of Salerno, reserving a census of d. 120 in favor of the Bishop of Cava; de Hoyeda took possession of it thanks to Francesco from Prignano, Baron of Aquarola in Cilento. The citizens emigrate because of the high tax burden.

The new baron, by his lieutenant, claimed the burial right in the church (8 pugs), and a plea. He had married the Spaniard Maria of Lion and had appointed his heirs grandchildren Didaco (Diego) and John, assigning to the second one the upholding of criminal jurisdiction entrusted to him by the prince Sanseverino and to Diego the civil jurisdiction.

Diego and Giovanni de Ogeda received the oath of allegiance on May 8, 1548 by Sant'Arsenio vassals of the church of St. Mary Greater. Diego did not reduce the first tithe, but only of 5 pugs the burial law. In 1549, another grant of chapters. Died in 1561, he was succeeded by his brother John who took possession on August 13, 1861, but the mayor refused to recognize him if he had notconfirmed privileges and chapters of the previous landowners.

Baron resorted to R. Chamber that ordered the dissection for peaceful possession.On 2 February 1606 the marquis bought the «state» of Diano by the marquis G. Battista Caracciolo of Brienza and gathered in the hands of a single overlord the civil and criminal jurisdiction of S. Arsenio.Local historians remember the misdeeds of the bandit Tittariello Verricella with its received about 300 villains.Dead Marquis F. Antonio Villano on 3 May 1668, inherited fiefs his cousin Maria Villano and son Fabio Colonna, Prince of Colobraro.

On May 8, 1683 the civil jurisdiction and mixed of Sant’Arsenio was granted to the regent Charles Caia for d. 5130. The Duke of Diano was obliged, however, to pay the canteen bishop of Cava: d. 122.80. In the same year the Duke Calà gave for testament the civil jurisdiction and mixed to his nephew Giovanni Maria Calà, preservating to the Dukes of Diano criminal jurisdiction. This jurisdiction, as it was said, had been to the Sanseverino, the barons of Diano.

Giovanna Sanseverino had been confirmed in 1463 by King Ferrante thepossession of S. Arsenio for all her life «et post eius mortem»his son Roberto «inter alia» the land of Diano with the hamlets of St. Arsenio and St. Peter « que nullo modo dividi possint a iurisdictioni terrae Diani ».On October 2, 1567 in Sant'Arsenio was made an instrument of division between the hamlets of Sant'Arsenio, St. Peter and Diano of the district Lake of Carusi.

On September 2, 1576 Nicola Grimaldi renounced in favor of his second son Merualdo the land of Diano with the title of Marquis. For debts incurred by Nicola and Merualdo Grimaldi the estate was auctioned and bought by d. 62,100 by Octavio Albino for Giulia Caracciolo, Marquise Brienza, who gave it up in favor of his son G. Baptista Caracciolo.

This, in turn, sold it to John Vi1lano, marquis of Polla. He gave it up in favor of his nephew Giovanni.Sale has not been finalized in 1614 if John Villano senior in that year gave the jurisdiction of weights, measures and Bagliva.The grandson kept the barony briefly. On November 11, 1625 for his too much debts became friar (regular clergy), so he gave up in favor of his brother to Polla with title of marquis and land ofDiano and hamlets with that of St. Peter, who was part of the «State» of «Polla. Passed to Calà, Charles Calà tried to sell the estate to Camilla Pignatella, sales could not be made for refusal ofthe r. assent. The feud then passed to Charles’s brother, Jerome.

He had been disinherited. This died in 1698 without heirs so arrived the taxation (dispute with a relative, Adriano Calà) that seized assets leased to Berlips Countess, wife of Hadrian Calà (meanwhile dead) and guardian of her son Marcello. He died in 1703 and the widowM. Brigida Spinola, Marquise Bamonte, guardian of his son CarloMary offered another 20,000 ducats if the IRS receded from lite. Donated the estate of the Diano R. Court (24 May 1703) was accepted the offer increased to d. 22,500 to be paid in three installments, for which Carlo Maria had actual possession of the fiefs. To Carlo Maria (m. 26 December 1783) was succeeded by his niece Bridget Calà (she was the daughter of his brother Marcello) who had married Vincenzo Schipani that inherited Diano 'maritale nomine».

Died in 1826 succeeded to him in the title his son Ignatius, to him followed (1866) William.Giustiniani says just a bit of Santarsiero or Santarzieri. He speaks about the 1750 inhabitants in his day, all farmers and shepherds, and informs us of the numbers from 1532 to 1669. A big epidemic had hit the village before 1648. The population in 1595 had 1065 inhabitants; in 1548it was reduced to just 400.