Jan Matejko's project for the Battle of Grunwald is an oil sketch. The next creative stage after drawing, when color is added to the line. The sketch shows a horse rushing straight ahead. This is the horse of the Grand Duke of Lithuania - Witold. In the finished painting, Witold is one of the most important figures, but in the sketch the horse prevails. His disheveled mane and absent eyes increase the expression. It is a capture of a moment that Impressionists would not be ashamed of.