The Sukumo Incident (Japanese: 粭島陰謀 Hepburn: Sukumojima inbō) was a coup against Ōuchi Yoshitaka, taking place during November, 1547. Led by Sue Harukata, a number of Ōuchi retainers and samurai led an attack upon Yoshitaka whilst he was at Kibune Shrine on Sukumo Island. Harukata’s assault was repulsed by Yoshitaka’s guards, and the conspirators fled from Yamaguchi. Ōuchi Yoshitaka would then grant his strategist, Masuda Fujikane authority to act in his name in order to round up those responsible. The aftermath of the incident was the execution of a large part of the Ōuchi court, leaving few resistors to Fujikane’s takeover of the clan after the battle of Notoro.
Background[]
Ōuchi Yoshitaka had become head of the Ōuchi clan following the death of his father, Ōuchi Yoshioki on January 29, 1529 at the age of 21. At first he proved a capable and energetic leader, leading campaigns against the Shōni Clan of Kyushu in 1536 and 1538 and extending his influence over Aki Province, much to the disdain of his rival Mori Mōtonari. Mōtonari would act against Yoshitaka by convincing a number of his vassals to betray the Ōuchi daimyō, either through bribery or simply coercion. This came to a head in 1544, when Kikkawa Okitsune and Ogasawara Nagataka both declared war on the Ōuchi clan whilst Yoshitaka was in Suō Province to the south. Luckily for Yoshitaka, the new head of the Masuda family, Fujikane proved a highly capable commander, defeating both Okitsune and Nagataka within half a year.
Yoshitaka named Fujikane as one of his chief Kokujin ryoshu (local jizamurai leaders) and under his counsel, chose to push his advantage against Mōtonari in Aki Province. Fujikane would win numerous victories in Yoshitaka's name, but it was during this time that the Ōuchi daimyō would slowly withdraw from public life. After the death of his older sister in 1546, Yoshitaka chose to adopt her son, Haruo. Haruo was sickly, however, and only lived for a further half a year before dying, likely of a fever. These two events seemed to have greatly affected Yoshitaka, who spent most of the following year isolated in his fortified residence, Ōuchi-shi Yakata conducting tea ceremonies and poetry. Without the clan leader's influence, morale fell amongst the campaigning samurai and Mōtonari was able to make some headway in pushing back into Aki Province.
The Ōuchi court split into two factions. One, lead by Masuda Fujikane and Yoshimi Masayori, supported Yoshitaka and wished to see him continue as clan head; acknowledging that he would need to be convinced back into the field. Another, lead by the headstrong Sue Harukata, instead wished to replace Yoshitaka with his son, Yoshinori. For much of 1547, the two factions politically warred, trying to influence other Ōuchi retainers to their side. Meanwhile, the Mori continued to push into Aki, compounding Yoshitaka's grief. By winter, 1547, the tension had reached a breaking point. Harukata, realising that Yoshitaka would likely never emerge from his depression, yet would also never step down as head of the clan due to the support of Fujikane, chose to take the decisive act of a coup.
Attack on Sukumo[]
That November, Yoshitaka was taking his annual pilgrimage along Oshima, towards Sukumo Island, visiting numerous shrines along the way. Harukata gathered roughly sixty men and silently pursued Yoshitaka along the peninsula, planning to trap him on Sukumo once he was at pray. Unfortunately for the attackers, the stormy winter weather meant that they spent longer than expected commandeering fishing boats and crossing the water to the island, giving Yoshitaka's guards time to assemble around Kibune Shrine.
According to legend, a local fisherman spotted Harukata's men and was going to ignore them, till he noticed that they had stolen his boat. He then rushed to Yoshitaka in rage and warned him of the samurai currently crossing the water. Yoshitaka quickly ordered the fisherman to take whichever boat he could find and sail across to Yamaguchi and warn them of their daimyō's peril. By this time, Harukata had managed to land on Sukumo and lead his men around the north side of the island, hugging the coast. However, he was sighted by Yoshitaka's guards as he passed along the bay by Ryu Shrine.
Yoshitaka sent a small group to hold the beach whilst the rest shored up Kibune shrine with defences. The fighting on the beach was brutal and although of the twenty or so men that held the beach, only six returned to Kibune, they had given Yoshitaka enough time to defend the shrine. Harukata's men desperately tried to enter the shrine but were repeatedly thrown back by Yoshitaka's guards. Tired from their prolonged fight on the beach and the freezing weather, Harukata and his men eventually fell back, retreating to the mainland.
Aftermath[]
Masayori was the first daimyō to arrive at Yamaguchi, followed by Fujikane and they were immediately ordered by Yoshitaka to round up the conspirators. Fujikane was granted full authority to act in Yoshitaka's name and he did so by rounding up thirty high ranking samurai, including Harukata and executing them. This left the Ōuchi court populated entirely by those loyal to Fujikane and his allies. Yoshitaka would be convinced to head back into the field in order to prevent this sign of weakness again.
However, by allowing Fujikane to purge his political rivals, Yoshitaka had left no opposition to his vassal's ambitions. Less than a year later, at the battle of Notoro, Yoshitaka would be betrayed and killed by Fujikane, essentially ending the Ōuchi clan.