during the early part of his reign, north xiongnu continued to be a constant threat to both han and her ally south xiongnu. emperor ming engaged in a variety of military and economic tactics to try to maintain peace with north xiongnu and was largely successful. in 65, he established a permanent border defense force, known as the duliao army (度遼營), in charge of protecting the northern boundaries and south xiongnu, and also to prevent the people of south xiongnu from defecting to north xiongnu.