Liber de apparitione Sancti Michaelis

The Liber de apparitione Sancti Michaelis in Monte Gargano (Bibliotheca Hagiographica Latina 5948) is a composite 9th century hagiographical text by an anonymous author containing the foundation myth of the Sanctuary of Monte Sant'Angelo, also known as Mont Gargano, on Mount Gargano, Italy, in northern Apulia. It contains record of the first known appearance of Saint Michael the Archangel in western Europe after the transmission of his cult from the Greek East.

The earliest extant manuscripts of the De apparitione are from the late eighth or early ninth century, but the tripartite composition of the text suggests at least three layers of narrative accretion; the oldest strata seems to go back to a lost sixth century version, which the author of the anonymous final version mentions in his recension.

There are three sections to the legend, recording three apparitions by Michael on Mount Gargano. The first and third sections appear to be part of the same narrative, while the second is possibly the account of a battle half a century later. According to the first and last parts of the legend, around the year 490 the Archangel Michael appeared several times to the Bishop of Sipontum near a cave in the mountains, instructing that the cave be dedicated to Christian worship and promising protection of the nearby town of Sipontum from pagan invaders. These apparitions are the first appearances of Saint Michael in western Europe.

The second section of the text describes Michael's intercession on behalf of the Sipontans and the Beneventans against invading pagan Neapolitans. Michael strikes the pagans with lightning, killing over 600 of them, and the Sipontans and Beneventans are victorious. Giorgio Otranto identifies this battle as the one recorded in Book 4 of Paul the Deacon's History of the Lombards, which describes the defense of the oraculum on Mount Gargano against 'Greeks'– Byzantine Neapolitan troops– by the Lombard Duke of Benevento, Grimoald I, on May 8, 663.

Richard Johnson summarises the legend:

The legend of the Archangel's apparition at Gargano is also recorded in the Roman Breviary for May 8, as well as in the Golden Legend (Legenda Aurea), the compendium of Christian hagriographies compiled by Jacobus de Voragine between 1260-1275. Its presence in the Golden Legend ensured its wide circulation in medieval Europe. This foundation myth may have influenced those of other Michaeline sanctuaries, such as the Revelatio Ecclesiae de Sancti Michaelis of Mont Saint-Michel.

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