As a layman and later as a priest, Philip would host informal prayer and discussion groups in his room. When his room became to small for the growing group they used a larger one, which they called 'the Oratory' (i.e. place of prayer). In addition to prayer and discussion, Philip's group served the needy of Rome. They would also occasionally go on excursions to other churches, often with music and a picnic on the way.
Some of Philip's followers also became priests, and in 1575 the Congregation of the Oratory was founded. Philip did not intend to found a new order, but instead directed that the community should live as secular priests without further vows. The Oratory spread; John Henry Cardinal Newman founded the first English-speaking house in 1848. First, however, the Oratory suffered accusations of heresy, centering on the idea of laymen preaching and the singing of vernacular hymns.
Philip was noted for his humility and humor, his popularity and his willingness to accept all people making an honest attempt to devote their lives to God, as well as his intense spirituality. He became one of the influential figures of the Counter-Reformation. While the Council of Trent reformed the Church on a doctrinal level, Philip called individual Catholics to reformed lives, including many leaders of the Church.
Feast Day: May 26
More here courtesy of the Catholic Online Saints Page