Mabillon speaks of a group of the Trinity in human form, sculptured by order of Abelard at the Paraclete. In it the Father wore a closed crown, the Son a crown of thorns, and the Holy Ghost a crown of olive. The group has long since disappeared, and there seems no other instance of the Holy Ghost in human form being represented with the olive. A dove bearing an olive twig could not be an emblem of the Holy Ghost unless the bird’s head were encircled with a halo. But Christian art uses the ancient symbol of peace repeatedly when illustrating Christ’s life upon earth. First we find the angel Gabriel bringing to the Virgin a branch of olive as token that his message is of peace. Sometimes he is also crowned with olive. He comes crowned with peace, and the branch in his hand foreshadows the reconciliation between God and man which is to come by the Child whose advent he announces. The olive branch took precedence of the lily as the symbol carried by the announcing angel. Originated probably by Simone Martini, one of its earliest instances is in his Annunciation now in the Uffizi. In the Florentine school the simple stick carried by the herald angel evolved, as we have seen, through the fleur-de-lys to the stem of lilies. In Siena it was the meaning of the wand, rather than the wand itself, which was developed. The wand simply marked that Gabriel was a herald; that it was a message of peace and goodwill which he brought was shown by the grey-green leaves of the olive. As a symbol it was by no means of Simone Martini’s own finding, for it was a very usual political symbol of the day, but he seems to have been the first to have placed it in the angel Gabriel’s hand, and the school of painting in Siena whole-heartedly and faithfully adopted his device. The general trend of Sienese symbolism was to direct devotion to the incarnate Godhead rather than to Mary of Nazareth, and it is of Him, as the bringer of peace on earth, that the branch of olive tells, as elsewhere the white lily proclaims the virginity of the coming motherhood. Then again, on that night when the angels sang of peace on earth and goodwill towards men-- ... ‘the meek-eyed Peace, She crown’d with Olive green, came softly sliding Down through the turning sphear.’[123] In one of the most naïve and fascinating of all Botticelli’s pictures[124] the angels crowned with olive hold up branches of it against the golden sky. Other angels, half distraught with joy, run with waving olive-sprays to greet the astonished shepherds. The same subject is much more soberly treated by Sano di Pietro.[125] One angel, flying through the twilight, brings a twig of olive to the shepherd who is sleeping on the hillside.