Photo/Illutration The code of conduct issued by warlord Hosokawa Tadaoki for retainers dispatched to assist in renovation work at Sunpu Castle is owned by the Kumamoto University Library. (Provided by Kumamoto University)

KUMAMOTO--"Bushido," the way of the warrior, was not the only edict samurai lived by in feudal times. Warlords also drew up additional codes of conduct to prevent feuding among their loyal retainers when they mingled with those from other domains.

Written documents uncovered here recently seem to underscore the Tokugawa Shogunate’s determination to reunite Japan after the nation was left divided by warfare.

According to an announcement by Kumamoto University, the written edit was created in 1608 by Hosokawa Tadaoki (1563-1645), the lord of the Kokura domain in what is now Fukuoka Prefecture, when his retainers were dispatched to repair Sunpu Castle in current-day Shizuoka. It included a ban on personal fights and excessive drinking.

The material was based on a draft drawn up by the Tokugawa Shogunate after the Battle of Sekigahara in 1600, which suggests the government's focus was on working toward unity after the country was torn apart by warfare.

In this context, the material is historically significant, experts said.

“The shogunate likely tried to prompt warlords to get along with each other by forcing vassals from different domains, which had been divided between friends or foes in the Battle of Sekigahara, to work together in one place intentionally,” said Tsuguharu Inaba, a professor of history at the university’s Eisei Bunko Research Center.

The regulations are also believed to reflect Tadaoki’s struggle to rein in his retainers.

Bearing the “kao” signature of Tadaoki, the original copy of the rules was discovered when the center was examining old documents previously owned by the Matsui family, which served as chief counselor of the Hosokawa clan, and then transferred to the university following the end of World War II.

The code comprises 13 articles stipulating that vassals must avoid fights with other clans at the behest of the government during the refurbishment work. Clan members who fought for any reason, as well as third parties involved in the conflict, would be punished.

It also warned that “individuals who go see other clan members’ fights will face a penalty.” Retainers were required to “obtain permission when going to town” and “drink at most three small cups of sake, though you can have meals together.”

The vassals were prohibited from “doing or watching sumo wrestling” and told to “travel in groups between Kokura and Sunpu” as well.

Similar conduct rules were developed by the Mori family in the Choshu domain in what currently is Yamaguchi Prefecture and the Maeda family in the Kaga domain in today’s Ishikawa Prefecture during the rebuilding program of Sunpu Castle.

Sunpu Castle is where Tokugawa Ieyasu (1542-1616) lived part of the time after his retirement.

Because the rules differ slightly in wording among the warlords, the clans likely released their own versions by modifying the draft distributed by the shogunate.

“The restrictions of the Hosokawa family are interesting, because they indicate Tadaoki’s tenacious temperament,” Inaba said.