大内義興の死と備芸石の動乱 : 享禄二年の安芸松尾城の高橋氏攻めと毛利元就

During the early half of the 16th century, the northern regions of Bingo and Aki and the eastern region of Iwami were 境目 (sakaime) or border areas where AMAGO in Izumo and OHUCHI in Yamaguchi were conflicting.
After OHUCHI Yoshioki died in December of the 1st year of Kyoroku (1528 A.D.), AMAGO Tsunehisa began to attack OHUCHI's 国衆 (kunishu) or land lords. First he beat the TAGANOYAMA family in the northern part of Bingo, and submitted them. Then AMAGO took the TAKAHASHI family on his side who had controlled large areas in Aki and Iwami, and who was the leader of the union of three provinces which were on OHUCHI's side. And TAKAHASHI also had marital relations with MOHRI and possessed an adjacent area near MOHRI's domain. In April of the 2nd year of Kyoroku (1529A.D.) TAKAHASHI who became to join AMAGO's side tried to confuse MOHRI's vassals and to divide them into two. It finally caused turbulences in the MOURI family.
In May, on the other hand, OHUCHI Yoshitaka (Yoshioki's heir) gave an order to his land lords that, as he would give MOHRI Motonari the position of the union leader which Takahashi had kept, all the land lords should cooperate with MOHRI in military actions. Then the ally of OHUCHI, MOHRI, SHISHIDO and WACHI warriors attacked the TAKAHASHI family at Matsuo Castle in Aki Province and TAKAHASHI was destroyed.
Recently a new report says that the attack was in May of the 3rd year of Kyoroku Era (1530 A.D.), but not of the 2nd year. The author wanted to make it clear. So, in this paper, some dozen old manuscripts in the 2nd and 3rd year of Kyoroku Era chosen out of the author's collections were studied more precisely and more concretely. After the respective affairs were placed according to the correct order of time, a whole image of those days could be pictured better. As a result it was proved that the date was May of the 2nd year.
The author also could clarify the contents of SUE Okifusa's (OHUCHI's chief vassal) letter dated May 28th of the 3rd year of Kyoroku Era, a part of which was taken to be the only basis of the new report. Actually that part meant SUE Okifusa's anxieties that TAKAHASHI's previous vassals and village warriors might raise a riot. But the main purpose in his long letter was not in that part, but in its last line where he ordered MOHRI to dispatch his warriors to Iwami in order to help his master OHUCHI because his castle in the eastern part of Iwami had been attacked. Therefore the results were as follows: ① the new report was concluded according to only a part of Sue Okifusa's letter, ② the reporter had not read through SUE's long letter, either, and in addition, ③ there were some unnatural steps toward his conclusion with not a few doubts on its evidences and arguments.
Generally speaking, the death of OHUCHI Yoshioki caused the attack to Matsuo Castle and the ruin of the TAKAHASHI clan. The most important historical phase was that, after the battles, MOHRI Motonari obtained the top position of the union of land lords in Bingo, Aki and Iwami on OHUCHI's side. And thereafter his leadership made the MOHRI clan gradually enlarge the areas under his control and finally destroy SUE and OHUCHI.