Siena of the thirteenth and fourteenth centuries was one of the great cities of Europe and its artists--Duccio, Simone Martini, and Ambrogio and Pietro Lorenzetti--were among those who reshaped the nature and place of painting first in Italy, then across Europe. Drawing on the extraordinary riches of Sienese archives, on early unpublished secondary sources, and on the recent work of historians, Hayden Maginnis situates early Sienese painters within...