Jun. 2 Tuesday of the Ninth Week of Ordinary Time; Optional Memorial of Sts. Marcellinus and Peter, martyrs, Opt. Mem.

Peter and Marcellinus are two Roman martyrs who suffered under the Diocletian persecution, about the year 303; the first was an exorcist, the second a priest. Their cultus was so important that after peace was restored to the Church, Constantine built a basilica in their honor. Their names are mentioned in the Canon of the Mass (Eucharistic Prayer I).