The Sengoku Period, 1560–1615: How Nobunaga, Hideyoshi and Ieyasu Unified Japan, on One Map

A Country of Sixty-Six Provinces and Two Hundred Lords

In the summer of 1560 Japan had an emperor in Kyoto, a shogun of the Ashikaga house who could barely hold the capital, and no government worth the name. Power lay with the daimyō: warlords who held a province or a handful of them, some heirs of old governor families (the Takeda in Kai, the Imagawa in Suruga, the Ōtomo in Bungo, the Shimazu in Satsuma), some upstarts who had pushed their masters aside (the Mōri in Aki, the Late Hōjō in Sagami, the Miyoshi round the capital). Between them sat hundreds of smaller lords, self-governing leagues such as the Iga ikki and the gunmen of Saika, and the armed temples of the Ikkō sect, who had ruled Kaga as a 'peasants' kingdom' since 1488 and whose head temple, the Ishiyama Hongan-ji, stood where Osaka Castle stands now.

The map follows the fifty-five years in which that patchwork was forced into one realm. Every district (gun) of the old provinces is coloured by the clan that held it, keyframe by keyframe, and the armies of the famous campaigns move across the map as stitched tokens. It is drawn in the embroidered tapestry style, which seemed fitting for a period that is still told, in Japan and far beyond, as a story of banners and family crests.

Nobunaga, 1560–1582

Oda Nobunaga started with half a province. On 12 June 1560 Imagawa Yoshimoto, lord of Suruga, Tōtōmi and Mikawa, marched into Owari with an army many times the size of Nobunaga's, and was killed in his camp at Okehazama by a surprise attack in a thunderstorm. His Mikawa vassal Matsudaira Motoyasu (the later Tokugawa Ieyasu) went home to Okazaki and became Nobunaga's ally. Nobunaga then took Mino from the Saitō (Inabayama, renamed Gifu, fell in 1567) and in November 1568 marched on Kyoto with Ashikaga Yoshiaki, whom he made shogun. The next decade was a war on all fronts: against the Asai and Asakura (Anegawa 1570, both houses destroyed in 1573), against the Ikkō-ikki of Nagashima, Echizen and the Hongan-ji (which held out until 1580), against Yoshiaki himself, whom he drove out of Kyoto in 1573, and against the Takeda. Takeda Shingen routed Ieyasu at Mikatagahara in January 1573 but died that spring; his son Katsuyori lost his army to Oda and Tokugawa arquebusiers at Nagashino in 1575.

By the spring of 1582 Nobunaga had destroyed the Takeda as well, and his generals were fighting the Uesugi in Etchū, the Mōri in Bitchū and preparing to cross to Shikoku. On 21 June Akechi Mitsuhide, one of those generals, turned his army on the Honnō-ji in Kyoto, where Nobunaga was staying with a small escort. For eleven days the map has an Akechi realm in Tamba, Ōmi and the capital. Then Hashiba Hideyoshi, besieging Takamatsu Castle by flooding it, made peace with the Mōri, brought his army back in about ten days (the 'Great Return') and beat Mitsuhide at Yamazaki on 2 July.

Hideyoshi, 1582–1598

Hideyoshi had no claim to Nobunaga's inheritance except his army, and he used it. At the Kiyosu conference he backed an infant heir and came out with the richest share of the Oda lands; in June 1583 he destroyed Shibata Katsuie, the senior Oda general, after riding his army 52 kilometres from Ōgaki to Shizugatake in an afternoon and evening. Against Ieyasu he fought a draw at Komaki and Nagakute in 1584 and won the peace instead: Ieyasu submitted in 1586. In 1585 Hideyoshi took Kii, forced Chōsokabe Motochika back into Tosa with three armies landing on Shikoku at once, and was named imperial regent. In 1587 he marched two armies totalling some 200,000 men into Kyushu, where the Shimazu had just overrun nearly the whole island, and in 1590 he besieged the Hōjō in Odawara for three months. When Date Masamune came to Odawara to submit and the northern lords were settled at Aizu that autumn, there was no independent daimyō left.

On the map, unification looks like a change of colour rather than of borders: most of the great houses (Mōri, Uesugi, Shimazu, Date, Tokugawa) kept their lands as Hideyoshi's vassals, and only the defeated or the abolished turn pale gold. The exception is Ieyasu, whom Hideyoshi moved in 1590 from his five home provinces to the former Hōjō lands in the Kantō, where he made Edo his seat. Hideyoshi then turned on Korea. The invasions of 1592 and 1597 are shown only as markers and a token at Busan, because the map stays on Japan; they ended when he died in September 1598, leaving a five-year-old son, Hideyori.

Ieyasu, 1598–1615

In the summer of 1600, while Ieyasu marched north against Uesugi Kagekatsu in Aizu, Ishida Mitsunari raised the western daimyō in Hideyori's name. For two keyframes the map shows nothing but the two sides: the Eastern army in light blue with the Tokugawa lands in navy, the Western army in wine red, Hideyori's own lands in gold and the Satake, who sat it out, in their own colour. The battle at Sekigahara on 21 October was decided at midday by Kobayakawa Hideaki's defection. Then the victors redrew the map: the Mōri were cut down to Suō and Nagato, the Uesugi to Yonezawa, the Ukita and Chōsokabe lost everything, and the Satake were moved to Akita in 1602. Ieyasu became shōgun in 1603. The last act was Osaka: a winter siege in 1614, a truce that filled in the castle's moats, and a summer campaign that ended on 4 June 1615 with the castle in flames and Hideyori dead.

How to Read the Map

Each colour is a clan's domain: Oda crimson, Takeda plum, Uesugi teal, Hōjō olive, Imagawa lavender, Mōri moss green, Chōsokabe orange, Ōtomo raspberry, Shimazu petrol blue, Date black, Tokugawa navy, and so on. Two families get a second, paler shade for the lords who fought under them: pale red for Oda allies, vassals and generals (1568–1583), and pale gold for the daimyō under Toyotomi rule. Grey stands for the smaller lords, leagues and temple domains that do not get a colour of their own. After Sekigahara, light blue marks the outside lords who had sided with Ieyasu, and navy the Tokugawa house and its own vassals. The tokens are the armies of the famous campaigns; hover over one to see whose it is.

The units are the districts of the old provinces, so no line is finer than a district, and a province shown in one colour was usually a mosaic of castles, some of which held out. Control in the Sengoku period was a matter of oaths and hostages as much as of garrisons, and in fluid regions (northern Kyushu in the 1580s, southern Mutsu, the Kantō between Uesugi and Hōjō) the map shows the most commonly accepted reconstruction rather than the only possible one. Dates are given as conventionally converted in Western literature: Julian before October 1582, Gregorian after.

How the Map Was Made

The borders are the provinces and districts of late Edo Japan from the CODH 'Former provinces and districts' dataset (旧国・旧郡境界データセット, built from the National Institutes for the Humanities' boundary data of Bakumatsu and Meiji maps, CC BY-NC 4.0). For each of about 140 areas, either a whole province or a group of districts where a province was divided, we recorded who held it at each of 44 historical moments, using Mary Elizabeth Berry's Hideyoshi, Jeroen Lamers' biography of Nobunaga (Japonius Tyrannus), George Sansom's History of Japan, volume 4 of the Cambridge History of Japan, Stephen Turnbull's Samurai Sourcebook for dates, and the Japanese Wikipedia articles on each province, clan and castle. More than a hundred castles, from Kiyosu and Kasugayama to Okō, Funai and Kagoshima, serve as test points that must lie in the right colour at every keyframe. The armies follow the dated itineraries of the campaigns.

Chronological Timeline

• 12 June 1560 — Battle of Okehazama: Oda Nobunaga kills Imagawa Yoshimoto
• 18 October 1561 — Fourth battle of Kawanakajima between Uesugi Kenshin and Takeda Shingen
• 1567 — The Mōri take Gassan-Toda; Nobunaga takes Inabayama and renames it Gifu
• 9 November 1568 — Nobunaga enters Kyoto and installs Ashikaga Yoshiaki as shogun
• 30 July 1570 — Battle of Anegawa; the Ishiyama Hongan-ji rises against Nobunaga
• 30 September 1571 — Nobunaga burns the Enryaku-ji on Mount Hiei
• 25 January 1573 — Battle of Mikatagahara: Takeda Shingen routs Tokugawa Ieyasu
• 1573 — Yoshiaki driven out of Kyoto; the Asakura and Asai destroyed
• 28 June 1575 — Battle of Nagashino
• 3 November 1577 — Battle of Tedorigawa: Uesugi Kenshin beats the Oda
• 10 December 1578 — Battle of Mimigawa: the Shimazu crush the Ōtomo
• 1580 — The Hongan-ji gives up Ishiyama
• 3 April 1582 — Takeda Katsuyori dies at Tenmokuzan
• 21 June 1582 — Honnō-ji incident: Nobunaga killed by Akechi Mitsuhide
• 2 July 1582 — Battle of Yamazaki: Hideyoshi defeats Mitsuhide
• June 1583 — Battle of Shizugatake: Shibata Katsuie destroyed
• May 1584 — Komaki and Nagakute; Okitanawate, where Ryūzōji Takanobu is killed
• 1585 — Hideyoshi takes Kii, Shikoku and Etchū and becomes imperial regent
• June 1587 — The Shimazu submit: Kyushu falls to Hideyoshi
• 17 July 1589 — Battle of Suriagehara: Date Masamune destroys the Ashina
• 4 August 1590 — Odawara surrenders; the Hōjō fall; Ieyasu moves to Edo
• 1592–1598 — Invasions of Korea
• 18 September 1598 — Death of Toyotomi Hideyoshi
• 21 October 1600 — Battle of Sekigahara
• 24 March 1603 — Tokugawa Ieyasu becomes shōgun
• 4 June 1615 — Fall of Osaka Castle: the end of the Toyotomi