Orthodox Christianity

Melania the Elder
She associated with heretics, so she was largely ignored by history even though she was not herself condemned. Melania the Elder (grandmother of Melania the Younger) founded monasteries and traveled from Spain to Rome to Egypt to Jerusalem, in contact with such leaders as Jerome and Paula and Augustine of Hippo.

Melania the Younger
Better known than her saintly grandmother, she talked her husband into celibacy after their second child died. They gave their immense fortune to found monasteries and do other good works, and left Rome ahead of the Visigoth invasions, going on pilgrimage to and settling in Jerusalem.

Olga of Russia
A cruel and revengeful ruler as regent for her son, she was the first Russian saint in the Orthodox Church, for her efforts in converting the nation to Christianity.

Theodora, Byzantine Empress
Empress of Byzantium 527-548, she was an actress before she caught the attention of Justinian, heir to Emperor Justin. The law had to be changed to permit him to marry an actress, and she went on to become one of the empire's most powerful women.