Sakanoue no Tamuramaro’s campaign and the surrender of Aterui

Since 774 the court had been at war with the Emishi of Mutsu, its north-eastern frontier province. In 789 an imperial army advancing towards the dwelling of Aterui in the Isawa region on the middle Kitakami was routed at Subuse; the Shoku Nihongi lists 25 killed in battle, 245 wounded and 1,036 drowned. A campaign in 794, in which Sakanoue no Tamuramaro served as deputy commander, is known only from a brief record. In 797 Emperor Kanmu appointed Tamuramaro sei-i taishōgun, ‘great general who subdues the barbarians’. He received the sword of command on 31 March 801 and marched north with an army that the Nihon kōki puts at 40,000; on 6 November he reported that the Emishi rebels had been subdued, and on 7 December he returned to Heian-kyō in triumph.

On 14 February 802 Tamuramaro was sent back to build a fortress in the conquered land, and two days later an edict settled 4,000 vagrants from ten eastern provinces at Isawa. On 19 May the court recorded his report that the Emishi chiefs Aterui and More had surrendered, ‘leading more than 500 of their kind’ — the date of the report in the chronicle, not of the surrender itself. On 11 August Tamuramaro arrived in the capital with the two chiefs. The generals asked that, as the captives wished, they be sent back to win over their followers, but the nobles objected that they had ‘the nature of wild beasts’ and could not be trusted, and that releasing them would be ‘raising a tiger and leaving trouble for later’. On 13 September 802 Aterui and More were beheaded in Kawachi province, at a mountain whose name the manuscripts write in different ways; historians such as Mabe Takahiro regard the mound in Makino Park in Hirakata, shown as their grave, as a modern invention.

Isawa Castle, a square fort some 670 m on each side, later became the seat of the Chinjufu, the northern military headquarters. In 803 Tamuramaro built Shiwa Castle farther north, but on 31 December 805, after a debate on ‘virtuous government’, Kanmu accepted Fujiwara no Otsugu’s argument that the wars and the building of capitals were exhausting the people, and a fourth campaign was called off. In January 812 Fun’ya no Watamaro declared an end to what he called thirty-eight years of warfare on the frontier.