This chapter explores how international humanitarian law and international human rights law initially developed independently, but have converged and are now deeply interwoven. Since ancient times, some who take part in armed combat have recognized that placing certain limits on the way in which they conduct hostilities can be advantageous. It can be a sign of civilized behavior, enhancing their own prestige; it may be a way to encourage their opponents to behave in a similar manner; and it may contribute to the reestablishment of peaceful relations in which the rule of law prevails. Whether or not these limits confer advantages, they do most often have the effect of asserting a commitment to humane principles.