The chapel which opens at the beginning of the right transept of the cathedral is the most important Marian shrine in Siena; it holds the image of Most Holy Mary of Grace Advocate of the Sienese, the work of the painter Dietisalvi di Speme and better known as the Madonna del Voto (“The Madonna of the Vow”). For centuries the Sienese have turned to her in moments of trial, whether personal or . . .