Saint Gallicanus was a Roman martyr in Egypt in 363 AD, during the reign of Julian.
A former general, he converted to Christianity and retired to Ostia where he was involved in a variety of charitable works.
[2] According to a Medieval legend, Gallienus was at one time the fiance of Constantine's eldest daughter, Constantia and was converted to Christianity by her soldier bodyguards John and Paul.
[3] He then retired to Ostia, endowed a church built by Constantine I, and founded a hospital where he worked with Saint Hilarinus.
There he washed the feet of the poor, prepared their table and served them, carefully waited on the infirm, and performed other works of mercy.