In the early years of the Spring and Autumn period, the rulers of the various states were the most important personages in the conduct of external affairs. They soon came to rely on their "xingren" (行人) or messengers to carry on most of the preliminary work in any matters of importance. These "xingren" were usually officials of fairly high rank within the state who carried out these commissions on a temporary basis. There were also the ambassadors, "shi" (使), who carried out more and more of the ceremonial duties of the ruler outside his state. Up until the first half of the Spring and Autumn period, however, the rulers themselves usually had to be present at the signing of any agreements which committed their states to any action. Reflecting the growing importance of external affairs, "xiang" (相) or chancellors, began taking a more active role in diplomacy. An indication of the growing power of the "xiang" was the fact that the chancellors of several states were able to repudiate a covenant which had been signed in 506 BC by the rulers of their various states. The culmination of this trend was reached later in the Warring States period, when the establishment of an external policy had become almost the exclusive concern of the chancellors.