"The Crucifixion"

Pietro Lorenzetti ( c. 1280 – 1348) or Pietro Laurati was an Italian painter, active between c. 1306 and 1345. Together with his younger brother Ambrogio, he introduced naturalism into Sienese art. In their artistry and experiments with three-dimensional and spatial arrangements, the brothers foreshadowed the art of the Renaissance. 

It was Pietro's frescoes which adorned the façade of Siena's Ospedale della Scala[5] that first bought him to the attention of his contemporaries. The frescoes – now believed to be the work of both Lorenzetti brothers – were destroyed in 1720 and subsequently whitewashed over.

His masterwork is a fresco decoration of the lower church of the Basilica of San Francesco d'Assisi, where he painted a series of large scenes depicting the Crucifixion, the Deposition from the Cross, and the Entombment. The massed figures in these pieces display emotional interactions, unlike many prior depictions which appear to be iconic agglomerations, as if independent figures had been glued onto a surface, with no compelling relationship to one another.