Natività della Vergine

This panel was finished around 1342 for an altar in Siena Cathedral, one of four commissioned in those years to honour the city's patron saints. Look at how Pietro Lorenzetti handled the frame. Instead of setting his scene inside the woodwork, he let the painted columns line up with the real ones, so the arches of the frame become the vaults of the room where Saint Anne has just given birth to Mary. A servant pours water, another warms herself by a fire in the next bay, and the tiled floor recedes as if you could step onto it. Painters had drawn interiors before, but few had made the frame and the picture share one continuous space this convincingly. Lorenzetti died a few years later, probably in the plague that swept Siena in 1348.