After divorcing his wife Minervina, Constantine marries Fausta, daughter of the retired Roman emperor Maximian.

Minervina
Minervina was either the first wife or concubine of Constantine I, and the mother of his eldest son and future caesar Crispus. Little is known of her life. Her birth and death dates are unknown.
Constantine the Great
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, decriminalising Christian practice and ceasing Christian persecution. This was a turning point in the Christianisation of the Roman Empire. He founded the city of Constantinople and made it the capital of the Empire, which it remained for over a millennium.
Fausta
Flavia Maxima Fausta Augusta was a Roman empress. She was the daughter of Maximian and wife of Constantine the Great, who had her executed and excluded from all official accounts for unknown reasons. Historians Zosimus and Zonaras reported that she was executed for adultery with her stepson, Crispus.
Roman emperor
The Roman emperor was the ruler and monarchical head of state of the Roman Empire, starting with the granting of the title augustus to Octavian in 27 BC. The term emperor is a modern convention, and did not exist as such during the Empire. When a given Roman is described as becoming emperor in English, it generally reflects his accession as augustus, and later as basileus. Another title used was imperator, originally a military honorific, and caesar, originally a cognomen. Early emperors also used the title princeps alongside other Republican titles, notably consul and pontifex maximus.