St. Pope Fabian was slain in 250 during the persecutions of Decius.
St. Sebastian, famous in sacred art for his arrow ridden body, was a Roman soldier murdered later in the 3rd century during the persecutions of Diocletian. St. Ambrose tells us about Sebastian in a sermon.
For your edification, there are a couple pieces of music I know which involve St. Sebastian, of contrasting styles and eras.
Guillaume Defuy (+1474) gives us a little motet, O Sancte Sebastiane. There is also Le Martye de saint Sébastien, controversial in its day for the avante-guarde performance choices.
You might like to hear them side by side, as it were…. well… forming a kind of Ambrosian sandwich. I’ll read a little Ambrose for you, from his Exposition of Ps. 118, in English first and then some Latin, to get our language into your ear.
Infirmitatem nostram respice, omnipotens Deus: et quia pondus propriae actionis gravat, beatorum Martyrum tuorum Fabiani et Sebastiani intercessio gloriosa nos protegat.