A short while ago, Baby Jesus was asleep, whereas now, his eyes are wide open for he can feel his mother pushing down her legs to get up and solemnly go towards her observer, to announce her divine regality. She still has the expression of an icon, fixed and lost in perfection. Contrarily Jesus with surprised and credulous eyes suspended in a tangible, everyday situation, is the sign of a change, the sign of the modernityof the young master who in this painting of 1319, the first work attributed to him with certainty, already reveals the important elements of his style. It is true that the artist turns to Giotto and the Florentine school but as a Sienese, he does not forget transparent color of his fellow artists, Duccio di Boninsegna and Simone Martini. This style becomes evident in a vigorous, expressive brushstroke and an almost reckless use of perspective, a problem presented by Giotto in Florence in a forced, ‘illusionistic’ key.
We are now standing in fron of a Madonna Enthroned by Ambrogio Lorenzetti, belonging to the cycle of frescoes entitled The effects of the Good and Bad Governance in Siena. He is a father of the primitive school of painting, even if his complex, ingenious nature of a restless experimental artist makes us consider him as one beyond the rigid attribution of an artistic, historical category.
The painting is now preserved in the Museum of Sacred Art of San Casciano, exposed in the church of Santa Maria del Gesú, where you can appreciate a small but select collection of masterpieces coming from the area of San Casciano.
Near Lorenzetti’s Madonna, there is a very rare altar frontal, depicting Saint Michael the Archangel and the Stories of the Legend by the Florentine Coppo di Marcovaldo, who can be considered the first master who, already in the first half of the 13th century, had felt the need to abandon the Byzantine, figurative stereotype. There is a mysterious, impressive Nativity, probably the work of the master of Cabestany. It is a marble torso, formerly in the church of Giovanni in Sugana, full of a primitive charm, typical of Romanesque figures.

See also: The Sienese Influence and Florentine Supremacy