Iron Age Celtic coins, mostly over 2,000 years old, were minted by the Celts from the late 4th century BC to the late 1st century BC, in gold, silver, and bronze (copper and tin). Many of them were stamped with the names of tribal rulers recorded in history only through their coins. Although their designs were influenced by Greek and Roman coinage, Celtic coins have their own sense of artistry and style. The images found impressed on Celtic coins vary from giants dragging heads on ropes, horsemen charging into battle or celebrating victories, gods and goddesses of many belief systems, chariots, many different kinds of animals, abstract patterns, kings and leaders, as well as elements such as lightning, and the sun and moon. They are tiny works of imaginative and vibrant art. The Insubres were a Gaulish tribe in Insubria, in what is now Lombardy, Italy and were the founders of Milan. The coin features a fierce lion image and may originate in the 3rd century BC.