The 40 Holy Martyrs of Sebaste are commemorated on March 9. Their martyrdom was in 320 under the Emperor Licinius, and St. Basil eulogized them only 50 years later in a homily on their feast day:

Homily on The Forty Martyrs

Wikipedia has this to say about the saints:

“A church was built at Caesarea, in Cappadocia, and it was in this church that Basil publicly delivered his homily. Gregory of Nyssa was especially devoted to the Forty Martyrs; two discourses in praise of them, preached by him in the church dedicated to them, are still preserved, and upon the death of his parents he laid them to rest beside the relics of the confessors. Ephrem the Syrian has also eulogized the Forty Martyrs. Sozomen, who was an eye-witness, has left an interesting account of the finding of the relics in Constantinople, in the shrine of Saint Thyrsus built by Caesarius, through the instrumentality of Empress Pulcheria.”

Those noble soldiers of the Master of all let us honor,
for they were united by their faith
as they passed through fire and water,
and being enlisted by Christ
they entered to divine refreshment.
Now those pious warriors stand and intercede
with Christ God for those who cry out.
Glory to Him that hath given you strength.
Glory to him that hath crowned you.
Glory to Him that made you wondrous,
Holy Forty Martyrs.

-Hymn for the feast