Flavia Julia Helena, also known as Helena of Constantinople and in Christianity as Saint Helena, was an Augusta of the Roman Empire and mother of Emperor Constantine the Great. She was born in the lower classes traditionally in the Greek city of Drepanon, Bithynia, in Asia Minor, which was renamed Helenopolis in her honor, although several locations have been proposed for her birthplace and origin.

Constantine I, also known as Constantine the Great, was a Roman emperor from AD 306 to 337 and the first Roman emperor to convert to Christianity. He played a pivotal role in elevating the status of Christianity in Rome, decriminalizing Christian practice and ceasing Christian persecution in a period referred to as the Constantinian shift. This initiated the cessation of the established ancient Roman religion. Constantine is also the originator of the religiopolitical ideology known as Constantinism, which epitomizes the unity of church and state, as opposed to separation of church and state. He founded the city of Constantinople and made it the capital of the Empire, which remained so for over a millenium.