The St. Apollinaris and Grisaille window
The top half of the window depicts something called the "Delestial Hierarchy", starting with Angels, Archangles, Principals, Powers, Virtues, Dominions, Thrones, Cherubin and Seraphim. The top depicts two angels adoring Christ. The lower half (minus the bottom two rows) depicts the life of St. Apollinaris, the first Bishop of Ravenna, including him being martyred by pagans. The bottom two rows were replaced in 1328 when Canon Cuillayme Theirry paid for an altar to be installed. The bottom row is an inscription telling of his generosity. The next row shows the altar's patron saints.