Several centuries after their arrival at Samarkand, the Sarmatians left a memorable impression upon the Romans, whom they battled near the Black Sea. The Romans defeated their nomadic rivals but afterward invited several thousand of them to join the Roman army. In the late second century A.D., when Marcus Aurelius needed to augment his forces to protect the northern border of the empire in Britain, he turned to the Sarmatians, 5,500 of whom were dispatched to guard against any potential attack by the Celts.