Battle of Sekigahara 1600 AD - Tokugawa Shogunate is Born

 

The 16h century was an age of almost constant struggle and turmoil for Japan.

 The so called Sengoku period of Japanese history was marked by intrigue, warfare and political upheaval that saw the rise and fall of many powerful warlords.

 Our story begins with the death of Toyotomi Hideyoshi, a renowned Samurai lord who was amongst the great figures that emerged during the upheaval.

 Toyotomi Hideyoshi served under another great Daimyo, Oda Nobunaga, who was one of the three so called “unifiers” of Japan.

 Toyotomi rose to prominence when he killed a turncoat general that caused the death of Oda Nobunaga.

 After avenging his master, he quickly consolidated control over Japan and embarked on an ambitious campaign on the Korean peninsula.

 Unable to attain the prestigious title of Shogun due to his humble origins, Toyotomi gained another illustrious title of Kampuku (the Imperial Regent).

 In May 1598 Hideyoshi fell ill and, anxious to secure his son’s succession and inheritance, he gathered his five most powerful vassals and made them swear an oath to care for his son Hideyori, and treat him as if he were Hideyoshi himself.

 A council of regents and five Bugyo magistrates, initially appointed to oversee the capital, would rule over Japan as Hideyori’s guardians until he came of age.

 Several months later, on September 18th, 1598, Hideyoshi died, leaving his young son Toyotomi Hideyori as his successor.

 The fact that Hideyori was only 5 years old at the time of his father’s death and that the prestigious title of Shogun was still vacant, created an entangled and complicated political situation of conflicting egos and interests that would lead to Sekigahara.

 When the dust settled, two factions emerged.

 The Toyotomi loyalists formed under the leadership of one of the Bugyo magistrates, Ishida Mitsunari, an inveterate schemer and court manipulator, while the opposing faction consolidated around Tokugawa Ieyasu, the most powerful warlord in Japan.

 Tokugawa moved first, advancing with his army to occupy the castles of Fushimi and Osaka, the latter being the residence of the young Hideyori.

 Needless to say, members of the council and other warlords viewed this move not only with great suspicion, but also as a step towards an actual usurpation of power – something they would not tolerate.

 The First sign of trouble was the failed assassination against Tokugawa, launched by Mitsunari, leader of the Loyalists.

 Strangely, the two men reconciled, with Tokugawa extending his forgiveness for the botched plot.

 But tensions escalated further in the province of Aizu, where one of the regents, the Samurai Daimyo Uesugi Kagekatsu, began fortifying his domains and building up his forces, actions that seemed like preparations for a revolt.

 Tokugawa demanded an explanation about the military build-up, but was largely ignored.

 And this, was not something that the powerful Damyo could ignore.

 Military preparations began at once… In July 1600, Tokugawa lead his army, which would come to be known as the “Eastern Army”, out of Osaka castle and headed east.

 Uesugi was the first daimyo who planned an open revolt, which was reason-enough for Tokugawa to march his troops towards Aizu in the humid summer heat, aiming to quell the rebellion before it spreads.

 By August 10th he reached Edo, where he remained while gathering more troops and consolidating his forces.

 Meanwhile, the conflict escalated further.

 On 22nd of August, MItsunari and the council of the Bugyo, together with 3 out of the 4 regents, sent a letter to him, containing 13 accusations and condemnations, among which was the fact that Tokugawa took up residence in Osaka castle, which was Hideyori’s own residence, acting as if it were part of his dominions.

 Despite the truthfulness of these accusations, Tokugawa declared war on Mitsunari’s coalition, which became known as the Western Army.

 Mitsunari, however, was prepared, and on that same day the Western Army took Osaka castle, while Tokugawa marched away to deal with Uesugi.

 Not long after, Mitsunari’s coalition occupied the Fushimi castle, after 10 days of stubborn resistance by the outnumbered defenders.

 Meanwhile, Tokugawa resumed his march east towards the Oyama castle, which was already under siege by his forces.

 The march of his 50,000 strong Eastern Army was unexpectedly slow, which might’ve seemed strange, considering that he was threatened from the west.

 But the sluggish advance was part of Tokugawa’s methodical plan.

 Namely, because he was uncertain about his enemy’s schemes and machinations, he bided his time, deliberately moving slowly to provoke his adversaries into revealing their exact intentions, while he was already under arms and on the march.

 Shortly before reaching Oyama, news arrived that the castle was taken and was under the control of his allies.

 On September 1st, Tokugawa established his base in the castle, and began making plans to deal with the loyalists.

 Mitsunari was also busy expanding his position.

 After taking Fushimi, he expanded his military operations, occupying strategically located castles.

 The Western Army was eventually able to advance against Ogaki castle.

 From there, Mitsunari intended to attack Tokugawa’s rear.

 While elements of the Eastern Army marched back to Edo, parts of the Western Army were able to capture Ogaki.

 Nearby, another two main roads were controlled by castles of Kiyosu and Gifu.

 If Mitsunari was to secure his position in order to advance against the Eastern Army, he needed to take these two key fortifications.

 But…

 Tokugawa was prepared for this eventuality.

 He assigned around 31,000 troops to garrison Kiyosu, already under the Eastern’s Army’s control, and to capture Gifu, which his troops managed to do on September 28th, after a brief siege.

 By securing his rear and choking the advance of the Western Army, the stage was set… Soon after, Tokugawa dispatched a force of 36,000 men, under the command of his son, to take the northern road.

 At the same time, he departed from Edo with his own host of about 30,000 on a forced march, in order to combine with his allies on time, a distance which he covered in only a fraction of the time he spent traversing this same path only a few weeks ago.

 The Western army was confined around the area of Ogaki castle when the first contingents of Tokugawa’s army began arriving in the plain that separated the two forces.

 The Eastern Army’s rapid advance apparently took Mitsunari by surprise.

 It seemed that Tokugawa would have the strategic upper hand after all.

 Tokugawa’s control of the castles guarding the two main roads meant that he was free to bypass Ogaki castle and march straight against the administrative and political bases of his enemy, rendering a pitched battle inevitable.

 After a brief skirmish ensued between the two armies near Ogaki, which turned out to be a victory for the Western army, Mitsunari decided to abandon his position and retreat a few miles westwards into a relatively narrow valley near a village of Sekigahara, intending to stop Tokugawa’s advance there.

 At dawn, on October 21st 1600, the opposing armies slowly took up their positions after marching throughout the rainy night.

 A dense mist covered the valley that morning and neither army could make out its’ enemy’s arrangement.

 The battlefield of Sekigahara was a predominantly marshy valley, surrounded by hills, with three rivers running through it.

 Mitsunari deployed most of his forces along the high ground that surrounded the western side of the valley with himself positioned on the left wing of his formation.

 The main bulk of his allies occupied mount Τengu.

 To the south, upon mount Matsuo, there sat a young lord by the name of Kobayakawa Hideaki, who would play a key role in the battle that was about to come.

 Namely, the young lord’s allegiance was wavering.

 At the beginning of the campaign he was on his way to unite his forces with those of Tokugawa, but was eventually convinced by Mitsunari to join the loyalists’ cause.

 However, he held and old grudge against Mitsunari while at the same time he owed a favor to Tokugawa.

 Neither of the two leaders could be certain who’s side would the young lord eventually take.

 The last position occupied by the loyalists was mount Nangu on the eastern side of the valley.

 The whole valley of Sekigahara was surrounded by loyalist forces…

 Tokugawa took a gamble, knowing that by marching into the valley, he could be entering a death trap.

 Nevertheless, the Eastern Army advanced through the dense mist and began taking positions around the village of Sekigahara opposite to the loyalist forces.

 While he forwarded a sizable vanguard, Tokugawa kept his own troops, some 30,000 men, as a reserve force behind his main line.

 Although exact numbers aren’t fully known, initially the Western Army numbered around 120,000 and held a strategically stronger position.

 On the other end, the Eastern Army was much more exposed and with its’ 75,000 troops it was significantly outnumbered.

 Tokugawa was further weakened due to the failure of his son’s large detachment to arrive on time to the battlefield.

 The battle that was about to take place near Sekigahara would be the largest concentration of Japanese Samurai in history… The two armies stood patiently for a couple of hours, waiting for the mist to clear.

 And, as the sun finally rose above the valley around 8 AM, both formations became visible.

 Then, a war cry from the side of the Easter Army pierced through the valley!

 30 mounted warriors, clad from head to toe in bright red armor, charged against the center of Mitsunari’s formation.

 This was the renowned red guard of Ii Naomasa, one of Tokugawa’s most loyal subordinates, also known as the “red devils”.

 Their charge was so fierce that they managed to reach the second line of Mitsunari’s formation.

 Others soon followed the charge of the red devils and the battle began in earnest.

 Several Eastern Army contingents attacked the palisades in front of Mitsunari’s position.

 This was perhaps where the fighting was most brutal, with Mitsunari’s own troops joining in.

 Meanwhile in the center, Tokugawa’s forces were causing heavy damage with their arquebuses being especially effective.

 However, the success of their charge left their flank exposed.

 Seeing this, an old Samurai lord by the name of Otani Yoshitsugu commanded his troops to attack the enemy’s flank, checking their advance.

 In the north, the right wing of the Eastern Army slightly began losing ground.

 Sensing that the time was right, Mitsunari ordered one of his allied contingents, commanded by Shimazu Yoshihiro, to attack.

 But Shimazu refused to move, apparently being amongst those Western Army generals who did not hold Mitsunari in high regard.

 Meanwhile, as the fighting in the center raged on, the Eastern Army’s situation worsened, as Mitsunari’s troops started gaining the upper hand, forcing their enemy back down Mount Tengu.

 During this turmoil, Tokugawa started bringing his own troops forward to Sekigahara.

 Some of his forces on the right managed to outflank the Western Army’s position by rushing around the palisades.

 The flanking maneuver immediately caused trouble for Mitsunari’s left wing, and his troops gave way, fearing they would be outflanked.

 This inadvertently forced Shimazu’s warriors into the bloody fighting on the front line, as they desperately tried to hold off the advance of Tokugawa’s right wing.

 At that moment Mitsunari saw the perfect chance to entrain a decisive blow against his heavily engaged enemy!

 He signaled to Hideaki, still sitting on mount Matsuo, to attack the Eastern Army’s left flank.

 But the young lord didn’t move.

 It appeared that his allegiance was to the other side.

 But, what happened next entered Japanese legend.

 Determined to force Hideaki into making a decision, Tokugawa ordered a detachment of arquebusiers to fire on his position.

 Amazingly, this gamble had an immediate effect on Hideaki.

 As if suddenly awoken from a slumber, he shouted “Our target is Otani!”, and then ordered his 15,000 men to charge down the mountain right into the already heavily engaged contingent of Otani’s men.

 The wily Old Samurai had suspected this treachery and moved some of his men to face a potential attack from Hideaki.

 But despite the heroic resistance of his troops, his position was eventually overrun.

 Faced with certain defeat, Otani committed suicide

 The Western Army was subsequently rolled up from its’ right wing and soon the attacking Hideaki reached the center of their formation.

 Unprepared to face an attack from the rear, Mitsunari’s center collapsed.

 Shimazu managed to organize a fighting retreat and his arqebusiers even wounded the attacking Li Naomasa who was forced to leave the battlefield.

 Meanwhile, Tokugawa sensed that victory was imminent and moved all of his troops forward to crush his enemy.

 With his army being overwhelmed all over the front, Ishida Mitsunari himself abandoned the battle and retreated.

 While the main forces of Mitsunari were being swept from the battlefield, his allies on mount Nangu never moved, remaining lodged on the mountain even after they observed the predetermined signal from Mitsunari.

 They could’ve probably turned the tide of the battle even after Hideaki’s defection, but upon hearing of the Western Army’s defeat they too retreated without engaging the enemy.

 The army of Tokugawa was triumphant.

 40.000 men from the Western Army lay dead while the Eastern Army lost around 7,000 troops.

 It was a closely fought battle that could have easily ended with victory for either side.

 What ultimately impacted the battle the most was the authority and respect that Tokugawa’s personality inspired in his contemporaries, which could not be matched by his rival Mitsunari.

 Soon after the battle Mitsunari was captured and executed.

 Tokugawa’s victory in the battle of Sekigahara brought an end to the Sengoku period of Japanese history, and when he took the title of Shogun, his dominance over Japan became undisputed.

 The Tokugawa Shogunate would rule a united Japan for the next 250 years, bringing a period of unprecedented continuous peace and stability… Special thanks to our friend Hoc Est Bellum for collaborating with us on this article.

 He also makes animated battles so make sure to check out his channel.