Watercolour and chalk on card. Unknown artist. Unframed. Measures approx. 16.25" x 12.5" (41cm x 32cm). There are what looks to be remants of some kind of adhesive in each corner to rear.

I removed the picture from it's old frame to see if there was any information about the artist on the picture's reverse, but alas not.

There are two artworks pictured on the Gettyimages website which are obviously connected to this picture.

The one is captioned thus:

"The retreat from Moscow 1812. Soldiers of the French Grande Armee fleeing the pursuing Russian army on the retreat from Moscow during the Napoleonic War of the Sixth Coalition on 10th November 1812 in Russia."

Napoleon's cypher 'N' surmounted with crown can be seen on the corner of the blue cloak. 

http://www.gettyimages.co.uk/license/521716671

http://www.gettyimages.co.uk/license/542417355

Napoleonic Wars: https://en.wikipedia.org/wiki/Napoleonic_Wars
1812 Retreat: https://napoleon1812.wordpress.com/page/2/