Antique Set of 11 metal Knight / Horse head Gamepieces

Does anyone know of an antique board game that uses only horse head or knight game pieces? I inherited this box of 11+ 1 horse head (or knight) game pieces from my grandfather 1889-1971. The box is made of wood, and has 11 cylindrical felt covered compartments to hold the game pieces. There is a 12th piece without a compartment to put it in (maybe there was a second box?) Each piece weights about 65 grams, and measures just under 2 inches tall. They are painted black with red bases, eyes, and mouths. There is a felt pad glued to the bottom of each. They do not seem to contain iron, a magnet had no attraction; maybe they are made of lead. He was stationed in France during WW1, maybe it could have come from there. The bottom of the box has the outline of a round label that used to be present. There are no other markings on the pieces or the box, I know nothing else about it. I would love to know what they were once used for.