戦国大名家
The great houses that divided Japan between them, and what happened to each one.
Sengoku politics was conducted by houses, not individuals. A clan was a family, its branch lines, its sworn retainer families, and the territory that supported all of them — and its interests outlived any single lord.
This is why so much of the period is about marriage, adoption and inheritance. Understanding who belonged to which house makes the wars far easier to follow.
| Clan | Territory (modern equivalent) | How it ended |
|---|---|---|
| Oda | Owari and the central provinces (Aichi and around Kyoto) | Fragmented after Nobunaga's death in 1582; absorbed by the Toyotomi |
| Toyotomi | Osaka and much of central Japan | Destroyed at the Siege of Osaka in 1615 |
| Tokugawa | Mikawa, then the Kanto plain (Aichi, then Tokyo) | Ruled Japan as shoguns until 1868 |
| Takeda | Kai and Shinano (Yamanashi and Nagano) | Destroyed in 1582 after the Battle of Nagashino |
| Uesugi | Echigo (Niigata) | Reduced after 1600; survived as the Yonezawa domain |
| Mori | The Chugoku region (Hiroshima and around) | Reduced to Choshu after Sekigahara; led the overthrow of the shogunate in 1868 |
| Later Hojo | The Kanto plain (Kanagawa, Tokyo, Saitama) | Destroyed at the Odawara Campaign in 1590 |
| Shimazu | Satsuma and southern Kyushu (Kagoshima) | Kept its domain after Sekigahara; led the overthrow of the shogunate in 1868 |
| Date | Southern Mutsu, later Sendai (Miyagi) | Ruled Sendai until 1868 |
| Imagawa | Suruga, Totomi, Mikawa (Shizuoka and Aichi) | Collapsed after Battle of Okehazama in 1560 |
| Chosokabe | Tosa and briefly all Shikoku (Kochi) | Dispossessed after Sekigahara; extinguished after Osaka |
| Otomo | Bungo and northern Kyushu (Oita) | Lost its domain in the 1590s |
| Sanada | Ueda, Shinano (Nagano) | Split in 1600; the Tokugawa branch ruled Matsushiro until 1871 |
At the centre was the main line, which held the house name and its titles. Around it were branch families, often founded for younger sons, and sworn retainer houses that held land in return for military service.
A clan's strength depended on how well those relationships were managed. The Mori placed sons at the head of two rival houses and converted them into supports. The Takeda lost cohesion when senior retainers stopped believing in their new lord, and the house fell within a decade.
Every house had a mon, a crest used on banners, armour and documents: the Oda's stylised wood sorrel, the Tokugawa's three hollyhock leaves in a circle, the Takeda's four diamonds, the Shimazu's cross in a circle.
These functioned as identification on the battlefield and as branding in politics, and many are still in use today by shrines, companies and cities.
Placing relatives on opposite sides of a conflict was a recognised strategy. The Sanada did it openly in 1600: father and younger son for the Western Army, elder son for the Tokugawa. The losing branch was condemned and then spared at the winning branch's request.
The same logic explains many marriages that otherwise look strange, including several between families actively at war.
真田昌幸 · 1547–1611
Beat Tokugawa armies at Ueda twice with a fraction of their numbers.
真田信之 · 1566–1658
The brother who chose the Tokugawa, and the reason the Sanada name survived.
真田信繁（幸村） · 1567–1615
Died attacking Ieyasu's command post at Osaka in 1615, and was called the finest warrior in Japan by his enemies.