Today the church celebrates St. Helena, widow, mother of Constantine the Great, and Founder of the True Cross.
Born in the mid third century, Helena married Constantius Chlorus, heir to the mighty Roman Empire. She gave birth to a son, Constantine, who stayed with her even when her husband was with another woman. When Constantius died, her son took over the Empire, and decreed that his mother be commended as mother of the sovereign (face on coins, etc.). Her son embraced Christianity through her influence, and they declared the Roman Empire for Christianity, finally putting an end to the persecution.
It is said that Helena went on many pilgrimages to the Holy Land, and had many Churches built over the sites where Christ died, was born, etc. There she discovered the very cross of Our Lord himself, and brought it back to Rome for veneration.
She is also well-known for her charitable works, and she died at the age of 80 around 330.