November 26th is the Feast of St. Sylvester the Abbot. It is in addition also the feastday of St. Peter of Alexandria, who was one of the first martyrs for combating the heresy of Arius. In the Divine Office a Commemoration is made of him.
Furthermore, in some places, it is also the feastday of St. Leonard of Port Maurice. The following account is taken from the St. Benedict Center:
Saint Leonard of Port Maurice was a most holy Franciscan friar. He lived at the monastery of Saint Bonaventure in Rome. He was one of the greatest missioners in the history of the Church. He used to preach to thousands in the open square of every city and town where the churches could not hold his listeners. The Immaculate Conception of the Blessed Virgin, the adoration of the Blessed Sacrament and the veneration of the Sacred Heart of Jesus were his crusades. He was in no small way responsible for the definition of the Immaculate Conception made a little more than a hundred years after his death. But Saint Leonard’s most famous work was his devotion to the Stations of the Cross. He is sometimes called the Saint of the Stations of the Cross. So brilliant and holy was his eloquence that once when he gave a two weeks’ mission in Rome, the Pope and the College of Cardinals came to hear him. Saint Leonard of Port Maurice also gave us the Divine Praises, which are said at the end of Benediction. He died a most holy death in his seventy-fifth year, after twenty-four years of uninterrupted preaching.Read more on his life at Nobility.org. And spend some time reading one of his greatest sermons: The Little Number of Those Who Are Saved by St. Leonard of Port Maurice.
Collect:
May the kindly prayers of Thy most holy Confessor, Leonard, avail us, O almighty God, before Thy Divine Majesty. Dutifully we venerate him: may we be helped by his intercession. Through our Lord...
Prayer Source: "The New Roman Missal" by Father Lasance