The Aso were a locally powerful clan on Kyushu island. The Aso were destroyed along with the Kikuchi clan by Otomo Sorin in 1554.
The Atagi were related to the Miyoshi clan and served the Mioyshi clan. They commanded ships for the Miyoshi clan. In 1562 the Atagi and Miyoshi were defeated in battle by the Hatakeyama clan and Atagi were forced to flee to Awaji island. Atagi Futuyasu was murdered on the orders of Matsunaga Hisahide as part of an attempt of Matsunaga to undermine the Miyoshi.
The Atobe were close advisors of the Takeda clan. After the demise of the Takeda clan, they came to serve the Tokugawa.
The Baba settled in Hitachi province. Another branch of the Baba clan was situated in Shinano province and fought battles with the Takeda clan, but eventually lost, and came to serve the Takeda. They ultimately came to serve the Tokugawa clan, after the demise of the Takeda in 1582.
The Bessho clan of Harima province were related to the Akamatsu clan. They had diplomatic ties with the Hatano clan. Initially the Bessho were allied to the Oda clan, but severed their ties with the Oda clan when a rebellion occured within their domain. Their domain was subsequently invaded by Oda forces and the Bessho were forced to surrender after their eventual defeat.
The Chiba clan settled in Shimousa province and they became a dominant force in the surrounding area for the greater part of the early Sengoku period. The power of the Chiba waned in the later part of the Sengoku period and ultimately they became vassals of the Hojo.
The Choskabe were initially vassals of the Ichijo clan based in Tosa province, but over the course of the Sengoku period, they came to rule all of Shikoku island. They were forced to submit to Toyotomi Hideyoshi when he invaded Shikoku island in 1584.
The Date clan settled in Mutsu and expanded their influence during the Sengoku period. The Date reached the height of their power under the reign of Date Masamune, nicknamed the one-eyed dragon of the north, because he missed an eye, after smallpox had robbed him of the vision in his right eye. Date Masamune waged war on the Hatakeyama clan, after the latter had kidnapped his father, while Masamune was busy practicing falconry. The Date came to serve Toyotomi Hideyoshi, but remained very powerful till the very end of the Sengoku period.
The Gamo of Omi province joined Oda Nobunaga and would grow powerful in the service of the Oda. They later came to serve Tokugawa and inherited large domains as a result of their service to both the Oda and later the Tokugawa.
The Goto were a minor Daimyo clan who controlled parts of Hizen province on the western shore of Kyushu island. They submitted to the Ruyzoji clan.
The Hachisuka of Owari province were related to the Shiba clan and later came to serve the Oda, when the Shiba clan was defeated. The Hachisuka fought in the battle of Nagashino and they aided Oda Nobunaga by attacking the warrior monks of Kii province.
The Hara originally came from Shimousa province. They first served the Chiba clan, but became retainers of the Takeda clan and later went on to serve the Tokugawa when the Takeda were destroyed.
The Hatakeyama were powerful supporters of the Ashikaga clan, but lost much of their power after the Onin war. Their holdings became scattered due to the Onin war. The Hatakeyama clashed with the Kasai, but later allied with the Kasai. They frequently clashed with the Date clan. The Hatakeyama saw their power diminish gradually over the course of the Sengoku period.
The Hatano settled in Tamba province and remained there until they were finally destroyed by Oda Nobunaga. They had diplomatic ties with the Bessho clan.
The late Hojo clan is not to be confused with the Hojo clan known from the days of the Hojo regency. Ise Shinkuro took the surname of Hojo and changed his name to Hojo Soun after he had conquered Odawara castle. In the early part of the Sengoku period the Hojo controlled Izu province, most of Sagami province and they started to exert some power in Musashi province were they clashed with the Uesugi. The Hojo constructed many castles and even more satellite castles to exert influence over their newly conquered territory. The Hojo managed to conquer Edo castle in Musashi province from Uesugi Kenshin, who prior had taken it from the Ota clan. When the Satomi clan attacked Kamakura, then held by the Hojo, a long standing feud developed between the Hojo and the Satomi that would last for decades. The Hojo were related to the Imagawa clan and had diplomatic ties with the Imagawa. The Hojo greatest achievement was at the battle of Konodai, where Hojo Soun managed to defeat an allied force of Ashikaga, Satomi and Uesugi men. At one time the Hojo power rivaled that of any clan, but Toyotomi Hideyoshi eradicated the power of the Hojo at the siege of Odawara in 1590.
The Honda clan from Mikawa province intially served the Imagawa clan, but switched sides to the Matsudaira clan, when the Imagawa were defeated by the Oda clan at the battle of Okehazama. The Honda would garner lots of fame as the most capable generals of the Matsudaira, who were later known as the Tokugawa. At the end of the Sengoku period the Honda held numerous fiefs throughout Japan.
The Horiuchi clan originated in Kii province and were able to expand their domain in Kii province when the power of the Hatakeyama clan declined. They allied themselves with the Oda and later came to serve Toyotomi Hideyoshi.
The Hosokawa were related to the Ashikaga and were staunch supporters of the Ashikaga Shogunate. The Hosokawa clan held the position of Kyoto Kanrei until they were finally eclipsed by the Miyoshi clan in 1550, who previously had been retainers of the Hosokawa. The Hosokawa power waned further, when Hosokawa Yoshiteru was assassinated in 1565 and the Hosokawa were forced to flee Kyoto when Oda Nobunaga attacked Kyoto in 1568. The remaining Hosokawa entered in the service of the Oda. Although related to the Akechi and still resentful over their loss of Kyoto, the Hosokawa chose not to support Akechi Mitsuhide when he murdered Oda Nobunaga, instead they chose to support Toyotomi Hideyoshi. The Hosokawa switched their support to the Tokugawa, due to the schemes of the Ishida. The Hosokawa were unable to hold their domain, when they were overwhelmingly outnumbered and ultimately were forced to surrender. The Hosokawa managed to delay their surrender and in doing so managed to prevent large numbers of troops from participating in the battle of Sekigahara, which helped the Tokugawa win the battle of Sekigahara.
The Ichijo acted as regents to the Emperor, but were forced to flee to their estates in Tosa province due to the Onin war. The Ichijo took advantage of the decline of the Hosokawa and at one time came to dominate Shikoku island. Their power declined when they were betrayed by their vassal Chosokabe and the Ichijo were forced to flee to Bungo province, where they allied themselves with the Otomo. Ichijo Kanesada converted to Christianity and with the help of the Otomo tried to reclaim his lands. He failed and was forced to exile.
The Ii were originally from Totomi province and were retainers of the Imagawa clan. After the Imagawa were defeated by Oda Nobunaga, they helped to destroy the Imagawa clan. Later they became vassals of the Tokugawa and Ii Naomasa rose to prominence as one of the Tokugawa four most famous generals.