The Board of Retainers (samuraidokoro) was also headed by a Senior Vassal Council member selected in the fourteenth century from among the Imagawa (who became a council member a little later), the Hosokawa, the Hatakeyama, the Shiba, and the Toki. The Board of Retainers had the responsibility over police functions and the execution of criminal justice in the capital of Kyoto. The office holder automatically became the "shugo" over Yamashiro province, the wealthiest and most densely populated in Japan, and had the responsibility of protecting the regime headquarters and the city of Kyoto. By the beginning of the fifteenth century, the head of the Board of Retainers was chosen from among four "shugo" families: the Yamana, the Akamatsu, the Kyogoku, and the Isshiki. The Board of Retainers did what the "kanrei" council system did: it connected the interests of the "shugo" lords to that of the regime, and thereby mediated potential conflicts between them. It was intermediary insofar as the sources of potential conflict to the regime, the "shugo" lords, became participants in an institution of the regime.