Stained-glass window V12 of Milan Duomo adorns the southern side of the Cathedral, where the altar of Saint John the Good stands, Archbishop of the Ambrosian diocese from 641 to 651. John the Good brought the Episcopal seat back to Milan following its exile in Genoa that lasted over a century caused by the invasion of the Lombards. The stained-glass window, the work of Giovanni Battista Bertini, depicts the Saint in glory and together with the two sides of the chapel, tells the story of the life of this figure particularly dear to the Milanese.