The Illerup Aadal weapon sacrifice mirrors the material world of a Germanic army from c. AD 210. Apart from the personal equipment and the weaponry of more than 400 warriors, it comprises four horses. The present paper gives the first conclusive analysis of the skeletal remains of these animals, involving osteological investigation and strontium isotope analysis. The results shed new light on the character of the sacrificial ceremonies which unfolded in the aftermath of Iron Age battles; on the nature of cavalry and its significance in Iron Age warfare; and on the much debated question as to where the army of Illerup Aadal had originally come from.