The one figure centrally involved in championing renga or "linked verse" as a courtly genre was Tonna's student Nijo Yoshimoto. During 1345-1372 Yoshimoto produced four major treatises aimed at drawing attention to renga as a literary art, providing it with a historical narrative that connected it to the earliest times, and analyzing it in aesthetic terms taken from similar works in the waka tradition. In 1392 the shogun Ashikaga Yoshimitsu arranged a rapprochement that ended the era of the divided courts and inaugurated a period of relative peace and prosperity for both the court nobility and the military aristocracy. Sogi, a Zen monk who, more than any commoner poet before, seems to have made an explicit decision to make a career for himself as a renga master. Given his emphasis on maintaining the proper atmosphere in a renga gathering, it is no surprise that Sogi is regarded as the first renga master to realize the full potential of the hyakuin.