[2] He was considered the most powerful figure during the Sengoku period before the rise of Oda Nobunaga, as Nagayoshi controlled the central government of the Shogunate.

He attacked the rebels in Nakajima in Settsu, which was led by Hosokawa Harukuni and the Hongan-ji Temple militant faction leader Shimotsuke Yorimori.

On January 14 of the following year, Nagayoshi, who was in Koshimizu Castle in Settsu Province, went to Kyoto, and the next day accompanied Hosokawa Harumoto to the shogunate.

On July 14, peace talks ended in failure, and Nagayoshi and Masanaga engaged in a small-scale battle near Myōshin-ji Temple.

Even as a subordinate vassal, the political power of Nagayoshi had grown to the point that he could essentially commanded the shogun himself to lead the armies from Settsu, Kawachi, Hokuriku, and Ōmi Province to Kyoto, posing a threat to his true superior, Harumoto.

[18] In 1541, Kizawa Nagamasa, who rebelled against Harumoto Hosokawa, went to Kyoto and pursued Shogun Yoshiharu and Harumoto, so the Shugodai (military governor) of Kawachi, Yusa Naganori, expelled Hatakeyama Masakuni, another Kawachi Shugodai who Nagamasa had supported, and welcomed his brother Hatakeyama Tanenaga, and declared his support for Nagayoshi.

Wada Shingorō, a vassal of Nagayoshi, was executed with the brutal punishment of being sawed alive due to accusations of adultery.

[27] After Shogun Yoshiharu's defeat and Hosokawa Harumoto's return to Kyoto, Nagayoshi made peace with Yusa Naganori and others through Sadayori's mediation.

[28][29][30] In 1548, on the 12th of the month, Nagayoshi asked Hosokawa Harumoto to pursue and kill Miyoshi Masanaga and his son, but his request was not accepted, so on October 28, he joined forces with his former enemies, Hosokawa Ujitsuna and Yusa Naganori, and rebelled against Harumoto, sending troops to the 17 Manors of Kawachi where they had a rivalry, and besieged Enokami Castle, where Miyoshi Masakatsu was holed up.

[6][d] In February of the following year, 1549, Nagayoshi beat the alliance of Hosokawa Harumoto, Miyoshi Masakatsu, and the Rokkaku clan, forcing them to retreat.

[41] On July 14, Nagayoshi sent a large army of 40,000 soldiers gathered from Settsu, Awa, Izumi and other provinces under the command of Matsunaga Hisahide and his brother, Matsunaga Nagayori, to engage the army of Hosokawa Harumoto in the battle Shokoku-ji Temple in Kamigyo Ward, Kyoto City, Kyoto Prefecture.

As a result of this battle, Yoshiteru and Harumoto were unable to return to Kyoto by force, and Rokkaku Sadayori, who supported them, began peace negotiations.

[49] In response to this, Nagayoshi announced an ultimatum to threaten any nobles or samurai clans that decide to follow Yoshiteru will have their domains confiscated.

[2] on November 30, after the assassination of Yusa Naganori, Yasumi Munefusa (Naomasa), who was appointed as the new shugodai (military governor), banished Hatakeyama Takamasa to Kii Province.

His eldest son, Yoshioki, was also promoted to Junior Fourth Rank and a member of the "Gosoubanshu" that same year, and the preferential treatment of the Miyoshi family by the shogunate and imperial court continued.

Taking the advantage of this gap, Hatakeyama Takamasa and Rokkaku Yoshikata, with Hosokawa Harumoto's second son Haruyuki as their leader, raised an army in July and attacked the Miyoshi clan from the north and south.

[73][74] In response, on March 6, Nagayoshi's eldest son, Yoshioki, and Matsunaga Hisahide evacuated Shogun Ashikaga Yoshiteru from Kyoto to Iwashimizu Hachimangū Shrine.

[76][74] Nagayoshi himself barricade his forces at Imoriyama Castle, as Yasumi Munefusa and the Negoro-ji Temple sect rebels besieged him.

Shigeari, who should have succeeded the Togo clan after Kazumasa's death, was chosen as the successor because his birth mother was the daughter of Kujo Tanemichi, who served as the regent, and it is believed that this good bloodline was the deciding factor.

[82] In December, another drawbacks for Nagayoshi occurred, as Hosokawa Ujitsuna, who was the nominal lord of the Miyoshi clan, died of an illness, and shortly before that, Hosokawa Harumoto also died of an illness, leaving the Miyoshi clan regime without Kanrei official that serves as their puppet in pulling the strings of government of Kyoto, which was necessary for the government to remain in power.

[86][g] As a result, on June 22, Yoshitsugu, who had become the heir, went to Kyoto to inherit the family headship, but as he returned to Imoriyama Castle immediately after paying his respects to Yoshiteru and others on the 23rd, Nagayoshi's illness appears to have already reached a terminal stage by this time.

[95] Modern political theorists John Ferejohn and Frances McCall Rosenbluth further said that the achievement of Nagayoshi in 1547 against his former lord, Hosokawa Harumoto, were quite overlooked in the study of late Sengoku-period.

[96] However, historian Hiroshi Sugiyama also said that the later years of his life, Nagayoshi has lost his fierceness due to focus with Renga poetry activities.

Sugiyama suggested that Nagayoshi was just similar to Nobunaga, who is tolerant with new system of faiths and had huge curiosity for exotic things.

There are references to Miyoshi Nagayoshi in books such as "Asakura Soteki Waki," "Koyo Gunkan," "Hojo Godaiki," and "Todai-ki.

", which portray Nagayoshi in a favorable light, and "Hojo Godaiki" places him on the same level as warlords of the following Sengoku period such as Oda Nobunaga, Akechi Mitsuhide, and Toyotomi Hideyoshi.

Historicities during this era began to relegate him as just a backdrop post-mortem character for the villainous and treacherous Matsunaga Hisahide, his top vassal.

[106] For long time, the prevailed opinions of Miyoshi Nagayoshi assessments tends to judge him as a mediocre ruler who allowed Matsunaga Hisahide to monopolize the central government.

[109] Furthermore, Nagayoshi was always compared to the "innovative" and "progressive style" of Oda Nobunaga reign, and is labeled as an old guard politician who is too conservative and cannot adapt to the rapid political changes and upheavals.

[3] Thus, modern era Japanese historians recently concluded that Miyoshi Nagayoshi was actually a capable Sengoku period leader, with some kind of "proto-Nobunaga" characteristic as he implemented several policies which were though as innovative during his time.