Were Italians to identify one monument in their culturally and linguistically diverse nation as representing its valhalla—the locus of their fatherland’s identity—it would be the great conventual Basilica of Santa Croce in Florence. Begun at the end of the thirteenth century during the meteoric rise of the Franciscan Order, the giant Gothic structure is surrounded by equally imposing monastic outbuildings and cloisters, as well as that jewel of Early Renaissance architecture, Filippo Brunelleschi’s Pazzi Chapel. The nave, transept, and chapels of the basilica tell a capsule story of Italian art—from Cimabue to Canova—while, lining those same walls, rows of tombs and cenotaphs recall human achievement in all its manifestations: from Dante to Alfieri, from Michelangelo to Galileo, and from Leonardo Bruni to Gioachino Rossini. Santa Croce is really more a pantheon of greatness than a...