Ludwig Richter (1803-1884) – The Well in the Wood at Ariccia Alte und Neue Nationalgalerie (Berlin)

The picture has something of this: mammal, people, tree, cavalry, group, wood, landscape, seated, man, woman, transportation system, herder, recreation, many, dog, river.
Perhaps it’s a painting of a group of people on horses in a wooded area with a man on a horse in the foreground and a dog.