Gelasius, son of Valerius, was a Roman citizen of African descent, very possibly Berber. If he was born in Africa, it would have been before the Vandal takeover in 439, or else he would not have been born a Roman citizen. Gelasius was an ordained priest and acted as secretary for Pope Felix III, writing many of his ecclesiastical documents for him.
Even before rising to the throne, Gelasius was known for his spirit of prayer and penance, as well as his solemnity and gift of study. He enjoyed the company of monks. And his greatest joy seemed to be justice and charity to the poor, to the point that he died penniless.
His relatively short papacy saw many changes in Europe. He was elected March 1, 492, during the civil war that succeeded Theodoric invading Italy in August, 489. The so called king of the Orthogoths, Odoacer, had been on the throne, ruling Italy, since 476 . Theodoric, acting as the representative of the new emperor, Anastasius, eventually assassinated Odoacer and was granted the position of viceroy to the emperor. The Goths administered Italy for the next 33 years, using the machinery of Odoacer's administration. Despite the civil war, this was a time known for peace and justice.
Gelasius was a writer, considered to be on the cusp of Late Antiquity/Early Middle Ages, a time we identify as the beginning of the Dark Ages, which really was not very dark, at all. He wrote one book on the dual Nature of Christ, supporting the Western view against the Monophysite Eastern heresy. He composed liturgical prefaces, hymns and collects. Today, there are 42 extant letters and fragments of many others. the subject matter is often the primacy of Rome.
Most importantly, Glasius wrote "Duo Sunt", a letter to Emperor Anastasius, a Monophysite, describing Church-State relations. In this letter, he acknowledged the superiority of kings, but also saying that the representative of God was the only one superior to a king. This letter had quite the political impact for the next thousand years.
In his pastoral work, Gelasius suppressed the Roman festival of Lupercalia, the feast of fertility and purification. In Latin, the verb "to purify" is "februare", hence the origin of our month of February. Lupercalia was in the middle of February. In order to allow new Christians to not give up their festival, Gelasius changed it to the Christian festival of the purification of Mary, forty days after Christmas, or February 2. And, it is said, he changed the middle of February to celebrate the feast of St. Valentine. Whether he did both or not is open to discussion.
The other pastoral act of this pope was to out the Manichaeans, a group which claimed to be Catholic at that time, yet were insisting on the impurity of various things, including sacramental wine. Gelasius insisted that the Eucharist be taken under both species. Those who would not partake, the Manichaeans, were exposed and then suppressed. Once this heresy was outed, and mostly eliminated, the discipline of receiving the Eucharist under one species only was returned to normal practice.
This pope died after only four and one half years on the seat of Peter. He died November 19, 496. His feast day is November 21, the day of his burial in St. Peter's. Unfortunately, archeologists and scholars do not know where in the church he is buried.
From "Duo Sunt":
"There are two powers by which chiefly this world is ruled: The sacred authority of the priesthood and the authority of kings. And of these, the authority of the priests is so much the weightier, as they must render before the tribunal of God an account even for the kings of men."