This church was originally founded by Galla Placidia herself, in fulfilment of a vow made by her to S. John Evangelist, when, on her way from Constantinople to Ravenna, she was in danger of shipwreck.[3] Agnellus tells us that of old the church bore an inscription to this effect, and he gives it to us: _Sancto ac Beatissimo Apostolo Johanni Evangelistae Galla Placidia Augusta cum filio suo Placidio Valentiniano Augusta et filia sua Justa Grata Honoria Augusta, Liberationis penculum marts votum solmentes_. The mosaic of the apse of old represented the incident. Unhappily the church was almost entirely rebuilt in 1747, only the tower of the eleventh century and the portico of the fourteenth being left as they had been. The beautiful fourteenth-century door, however, bears above it a relief of that time in which we see Our Lord, S. John Evangelist, Valentinian III., Galla Placidia with her soldiers and her confessor, S. Barbatian, with priests. Below this on either side of the arch of the doorway is a representation of the Annunciation and within the arch itself a relief which recounts the miracle which attended the consecration of the church. For the church of S. Giovanni Evangelista was not only founded in recompense for a miracle, but a miracle attended its consecration. It seems that when the church was to be consecrated no relic of S. John Evangelist was to be had. Therefore the Augusta and her confessor gave themselves a whole night to prayer, and suddenly there appeared to them S. John himself, vested like a bishop with a thurible in his hand, with which he incensed the church. Then when he came to the altar to incense it, and they would have venerated him, he suddenly vanished, only leaving in the hand of the Augusta one of his shoes. This legend, which is represented in relief in the fourteenth-century doorway of S. Giovanni Evangelista, is also the subject of a picture by Rondinelli of Ravenna in the Brera at Milan. [Footnote 3: See _supra_, p. 41.] The church has, as I have said, been ruined by the rebuilding of 1747; but there still remain the twenty-four columns of bigio antico with their Roman capitals, which upheld the old basilica, and in the crypt is the ancient high altar of the fifth century. Something, too, of the old church would seem to remain in the much repaired walls of the apse without. [Illustration: THE CAMPANILE OF S. GIOVANNI EVANGELISTA] The frescoes by Giotto, sadly repainted, in the fourth chapel on the left, must be noted. They represent the four Evangelists with their symbols over them, and the four Latin fathers of the Church, S. Jerome, S. Ambrose, S. Austin, and S. Gregory. Certain fragments of a thirteenth-century mosaic pavement are to be seen in the chapel of S. Bartholomew, which is itself perhaps the oldest part of the church.