Boniface was a native Roman, son of a presbyter, Jocundus (maybe Secundius). He was elderly at the time of his consecration. We know this because he was ordained by Pope Damasus, who ruled 366-384. So, he had already served as a priest for at least 34 years. It is most likely that Boniface served as papal legate to Constantinople under Pope Innocent I, when that pope intervened in the ongoing problem with John Chrysostom, who was deposed as bishop.
Boniface was a man of unblemished character, esteemed for his charitable and learned personality. He had been well versed in the discipline of the Church before he was elected. An elderly and sickly man, his only short-coming was that he equated bodily cleanliness with the luxury, materialism, paganism and sensuality of a dying Rome.
Unfortunately, lack of regulations and politics ruled the Church at this time. The first demonstration of this was on the day Boniface was elected. Pope Zosimus had been dead and buried only hours when it was obvious that there was a problem. Zosimus was a rather divisive person who had not healed the divisions that had been created in Rome by the time he died. No sooner was the old pope buried than the deacons and other lower ranking clergy went to the Lateran where supporters of the deacon Eulalius were waiting. They immediately voted him bishop of Rome. The new bishop and his supporters stayed in prayer at the church, waiting for Sunday, the traditional day for consecrations. Meanwhile, across town, at the Church of Saint Marcellus, other bishops and a majority of the priests, elected Boniface bishop. Each was consecrated in their respective churches that Sunday, December 29.
Two bishops of the same city is not a good start. The urban prefect warned both parties to keep the peace while he wrote to Emperor Honorius for clarification. The letter said that Eulalius was elected first and in due order, therefore this man was in the right. The emperor responded within a few days agreeing with the prefect. The citizens were not in agreement and the announcement lead to violence in the streets. The prefect's soldiers took Boniface into custody outside the city. When Boniface's supporters wrote to Emperor Honorius about irregularities in Eulalius' election, the emperor had him taken from the city, too. Honorius reversed his decision and met with both men, deciding on a synod to determine the outcome. It may very well have been Eulalius who became true pope except for one thing. Eulalius and supporters marched into Rome in time for the Easter celebrations, ignoring the emperor's instructions to stay out of town until the synod was called. Eulalius immediately lost the favor of the emperor and his counsel. Boniface became the accepted pope immediately, 15 weeks after his election.
Boniface only had three and a half years to accomplish his papal work, suffering from illnesses at the same time.
A friend of Augustine of Hippo, Boniface encouraged his friend to write against Pelagianism, the argument that original sin does not exist and that people do not need grace for salvation. Augustine dedicated several of his books to Boniface. This pope achieved more in his fight against the heresy that his predecessor who had offended the African bishops.
Bishop Boniface was a strong proponent of papal authority. His comment, "It has never been lawful for what has once been decided by the apostolic see to be reconsidered" became the basis for the principle of "Rome has spoken, the matter is settled".
Due to a misquoted mandate, Boniface was able to revoke powers that Zosimus had given to Gaul, that being one bishop was papal delegate and all communication from Gaul had to go through him.
Boniface enforced laws forbidding slaves to be clerics; he reinforced legislation dictating that women should not handle altar linen or minister incense. With great zeal, he organized discipline and control.
Boniface was buried in the Catacomb of St. Maximus on Via Salaria, near the tomb of St. Felicity, whom he revered.