Together with Florence, Siena was the chief economic, political, and cultural center of Tuscany in the late Middle Ages and early Renaissance. Although only in 1559 did Siena become part of the Grand Duchy of Tuscany under the rule of the Medici, its heyday was unquestionably two centuries earlier, between 1287 and 1355, when the independent commune was ruled by nine magistrates (referred to as the nove) drawn from a restricted oligarchy. During this time of peace and prosperity—interrupted by the devastating plague of 1348 that reduced the population by more than half—the city allied itself with the papal party of the Guelphs and had contacts with the Angevin dynasty in France and Naples. These political ties help explain the pronouncedly Gothic character of so much Sienese architecture and the fluent elegance of its paintings.
No other city outside Florence produced a comparably great school of painting, culminating in the figures of Duccio di Buoninsegna (active by 1278, died 1318), Simone Martini (active by 1315, died 1344), and the brothers Pietro and Ambrogio Lorenzetti (active 1320–44, 1319–47, respectively). Duccio may be considered the father of Sienese painting and is, together with Giotto, one of the founders of Western art. His paintings introduce a lyrical note and a refined sense of color into European painting, and he was an unsurpassed story teller, or narrative artist. Although his early work shows a profound debt to Byzantine precedent, after about 1295 or 1300—the date of a Madonna and Child in the Metropolitan —his paintings show an increasing interest in space and an exploration of human emotions. The enormous altarpiece he painted for the cathedral of Siena—the Maestà—is one of the landmarks of European painting. On the front it shows the Madonna and Child enthroned with saints and angels, while on the reverse (facing the choir, where the clergy sat during services) were more than fifty scenes of the life of Christ, incorporating urban views, landscapes, and interior settings of astonishing invention. (The altarpiece was cut apart in the eighteenth century and partly dispersed; one scene is in the Frick Collection, New York.) Just as Giotto’s frescoes in the Arena Chapel, Padua, and in the Church of Santa Croce, Florence, forecast Florentine painting for the next two centuries, so Duccio’s Maestà became a reference point for all Sienese artists. In it, two strands of European art come together: the otherworldly, sacred art of the Middle Ages, and the human-oriented art of the early Renaissance.
Simone Martini developed the lyrical vein in Duccio’s art. An artist of incomparable refinement and descriptive abilities, he became one of the most sought-after painters of the day, dying at the papal court in Avignon, France, and famously praised by the great poet Petrarch. The richly tooled surfaces of his paintings and their elegant naturalism became the basis of courtly art from Paris to Prague—the so-called International Gothic style . Simone’s brother-in-law, Lippo Memmi (active by 1317, died 1356), sometimes collaborated with him and was an artist of almost equal caliber . Each had a brother (Donato Martini and Federigo Memmi) who also painted and scholars have not yet agreed on assigning various works of outstanding quality to them. Of these, by far the most important is a fresco cycle in the Collegiata of San Gimignano.
Pietro and Ambrogio Lorenzetti stand somewhat apart from this Duccesque tradition, though Pietro almost certainly worked on the Maestà. Their emphasis on deep and complex spatial settings and three-dimensional figure construction derived from their close study of the work of Giotto . Each excelled as a fresco painter. However, like Duccio and Simone Martini, they had a native feeling for rich color harmonies, and their work shows a precocious interest in genre-like details. The deeply expressive character of their art unquestionably reflects the sculpture of Giovanni Pisano, who was active in Siena from 1284 (his last record of payment there was in 1314). Ambrogio Lorenzetti’s paintings are perhaps the first in Europe to employ a single-point perspective. Fifteenth- and sixteenth-century Sienese painters looked increasingly to Florence for inspiration, but outstanding artists such as Sassetta , Giovanni di Paolo ; ; , Neroccio de’ Landi , Matteo di Giovanni, and Beccafumi maintained the great tradition established by their fourteenth-century forebears.