St. John Evangelist, Ravenna: Exterior detail, 14th century Gothic marble portal

San Giovanni Evangelista was commissioned by the empress Galla Placidia in fulfillment of a vow she made during a storm in 424 while sailing from Constantinople to Ravenna. She came to Ravenna to assume the government of the western Roman empire on behalf of her young son, Emperor Valentinian III. In about 600, the basilica was expanded by incorporating the narthex into the church and the interior was redecorated under Archbishop Marinianus (ca. 598-606.) Further renovations were done throughout the Middle Ages (when it was part of a Benedictine monastery) and in the Baroque period. It was heavily damaged in WWII bombing and rebuilt.