Saint Helena of Constantinople, also known as Saint Helena, was the mother of the Roman Emperor Constantine the Great. She is best known for her role in promoting Christianity within the Roman Empire during the early 4th century. Helena is often credited with finding the true cross, the cross upon which Jesus Christ was crucified, during her pilgrimage to Jerusalem. Helena's efforts significantly contributed to the establishment of Christianity as a major religion in the Roman Empire. She is venerated as a saint in both the Eastern Orthodox Church and the Roman Catholic Church, with her feast day celebrated on August 18. Her legacy includes the construction of important churches, such as the Church of the Holy Sepulchre in Jerusalem.