The Virgin of the Rocks was commissioned (not long after Leonardo's move to Milan) by the Franciscan Confraternity in the Church of San Francesco Grande. Leonardo was assisted by two local artists, the Predis brothers, their task was to create an altarpiece for the recently completed chapel dedicated to the Immaculate Conception of the Virgin Mary. The Predis brothers completed two side panels while da Vinci painted the centre panel.
Shortly after the altarpiece was finished the artists became embroidered in a dispute about payment resulting in the artists threatening to sell the work to a rival bidder. It is likely that this dispute resulted in the making of the second version of the Virgin of the Rocks. This is the one now in the National Gallery in London, and in fact, it was the London Virgin that was placed in the chapel in San Francesco Grande. The original Paris version was quickly sold to an art lover soon after completion.
The subject of the paintings is a legendary meeting between the infant Jesus and John the Baptist on the flight into Egypt. The Madonna is at the centre of the composition with Jesus seated with the angel Uriel his arm raised in blessing, John's hands are seen clasped in prayer.
I have seen both paintings and do not really have a favourite, although the London version is more tightly finished than the one in the Louvre, I like them both.
How's that for sitting on the fence? The brushwork and contrast between light and dark (chiaroscuro) is typical Leonardo and standing before these paintings you do feel the power and the presence of the renowned artist. It really is shiver up the spine time!