The immigrant monk Mugaku Sogen(無学祖元), who predicted a second Mongol invasion, yelled at the Kamakura Shogunate's regent, Hojo Tokimune(北条時宗), one month before the outbreak of the Koan Invasion (弘安の役1281), "Do not be troubled by worldly desires, and go straight." This time, let's take a look at Mugaku Sogen's koan, "Do not be troubled by worldly desires, and go straight."

In the early 12th century, when the territory of Islam was expanding rapidly, the legend of Prester John, who ruled a major Christian country in the East, was born. Prester means a clergyman or priest, and the Latin word is Presbyter Ioannes, meaning John the Priest or John the Priest-King.

In 1122, Archbishop John of India's Eastern Church met with Pope Callistus II and reported on the thriving Christian church in India.

In 1145, Bishop John Hugh of the Syrian Antiochian Church met with Pope Eugene III and reported that King Prester John had defeated the Turkish army near Samarkand and attempted to rescue Jerusalem, but was unable to do so due to the flooding of the Tigris River. This prompted the Pope to call for a Second Crusade.

In 1165, letters from Prester John were sent to Pope Alexander III, Byzantine Emperor Manuel I, and Holy Roman Emperor Frederick I. As a result, twelve years later, a papal mission was sent from Venice with a reply to Prester John, but John seems to have not responded.

According to the Franciscan missionary and explorer William of Rubruc and Marco Polo's Travels, the Nestorian priest and Kerait ruler Prester John was Temujin(Genghis Khan's real name)'s foster father. In this legend, the Kerait ruler Tugrul is identified with Prester John.

Temujin's father Yesugei died in 1171 when Temujin was 9 years old. Tugrul had fostered the future Khan after the death of Yesugei and was one of his early allies, but the two had a falling-out.

Temujin was chosen as the Khan to lead the nomadic tribes of the Mongolian Plateau in 1189. Temujin asked for his son to marry the daughter of Prester John's younger brother, Vut, who was his ally. However, Prester John was enraged by the demands of a low-ranking vassal and refused Temujin's request. In 1203, a war broke out, in which Prester John was defeated and his country (the Kerait tribe) was destroyed.

Temujin captured Sorghatani-Beki, the daughter of Tugrul's brother Jaka-Gamb, and married her to his son Tolui. The couple had several children, including Möngke(the fourth Khan), Kublai(the fifth Khan), Hulagu, and Ariq Böke.

In 1206, Temujin held a kurultai gathering the leaders of various tribes upstream the Onon River near Khukh-Nur, and ascended to the throne as Genghis Khan, the ruler of all the tribes, and established the Mongol Empire. The name Genghis is an honorific given by a shaman named Kokochu Teptenguri, and there are two theories about its origin: one is that it comes from tenggis (or tengiz), which means "sea" in Turkic, and the other is that it means "the one who rules the world."

Genghis Khan, who had expanded his power to the Mongolian Plateau, Southern Siberia, and Central Asia, renamed his country "Yeke Mongol Ulus (Great Mongol State)" and launched an all-out invasion of the Jin Dynasty(金朝). The Jin Dynasty abandoned Zhongdu (中都later Dadu大都/Beijing北京) and moved its capital to Kaifeng(開封) in Henan(河南). Genghis Khan invaded the oasis countries of Central Asia in 1218 and destroyed the Khwarazmian Shah Dynasty, but died in battle during an expedition to Western Xia(西夏) in 1227.

The third son, Ogedei, who was supported by the fourth son, Tolui, who inherited 80% of Genghis Khan's direct army based on an imperial decree issued during Genghis Khan's lifetime, became the second emperor in 1229 and established the capital in Karakorum. He took the imperial title "Qa'an" (later Khan), derived from the ancient Khagan (qaγan).

At the Kurultai held in Karakorum in 1235, a resolution was made to invade the Southern Song Dynasty and Europe. The European Expeditionary Force defeated the allied European forces of the Kingdom of Poland, the Holy Roman Empire, the Knights Templar, the Teutonic Knights, and the Knights of St. John at the Battle of Wahlstatt, but returned to Mongolia following the death of Ogedei in 1242.

Because Ogedei's third son Kuchu, who had been appointed as his successor during Ogedei's lifetime, died during an attack on the Southern Song Dynasty(南宋), Ogedei's empress Dregene supported her own son Guyuk as the third emperor, but this led to friction with Kuchu's eldest son Shiremun and Batu, the second son of Genghis Khan's eldest son Jochi and the commander of the European expeditionary force. However, Guyuk died in 1248, just two years after ascending to the throne.

Pope Innocent IV, who became Pope in 1243, two years after the Mongol army defeated the combined Polish and German forces at the Battle of Wahlstadt, called for a crusade against the Mongol invasion, while at the same time drawing up a plan for both peace and war to cooperate with the Mongol army and attack the Islamic army from both sides, and dispatched Franciscan priest Giovanni de' Plano Carpini as an envoy in 1245. Carpini entered Russia from Poland and arrived in Karakorum in 1246 after a journey of one year and three months, and returned to Lyon in the autumn of 1247 with a reply letter from the third Khan Guyuk addressed to the Pope.

Güyük's wife Empress Ogürgaimish tried to select an emperor from the Ögedei family, but Batu wanted to appoint his uncle Tolui's eldest son Möngke as emperor, and conflict between the two factions continued.

Batu, in consultation with the Tolui family and the three eastern royal families, held a kurultai at Kode-e-Aral and selected Genghis Khan's fourth son, Tolui, and his wife, Sorkhoktani-Beki's eldest son, Mongke, as the fourth emperor.

After ascending to the throne, Mongke executed or purged opponents of the Ogedei and Chagatai families, including the previous emperor's wife Ogurgaimish, Shiremun, and Yesu Mongke.

Mongke appointed his second brother Kublai as the Grand Commander-in-Chief of the South Desert Han region(漠南漢地大総督), and planned to conquer the Southern Song Dynasty(南宋). He also appointed his third brother Hulagu as commander-in-chief of the Western Army(征西方面軍総司令官) and had him invade Iran, destroying the Abbasid Caliphate in 1258.

However, fearing his capable younger brother Kublai, he replaced him, which delayed the conquest of the Southern Song Dynasty. Mongke personally set out in 1258, aiming to conquer the Southern Song Dynasty from the Sichuan area, but after capturing Chongqing at the end of July the following year, he suddenly died in his camp at Diaoyu Mountain in Hezhou. As he had not left a will regarding a successor, a dispute over the succession to the throne broke out, and the Mongolian forces that had been attacking the Southern Song Dynasty withdrew all at once from all fronts.

After Mongke's death in battle, his younger brother Kublai, who had led a separate force to attack the Southern Song Dynasty, ascended to the throne at Jinlianchuan(金蓮川:Shangdu上都/Kaiping開平: currently the southern part of the Zhenglanqi正藍旗 of the Xilingol League, Inner Mongolia Autonomous Region, People's Republic of China). When this happened, Ariq Bukhe, the youngest brother of the Tolui family who was defending the capital Karakorum, also declared his accession to the throne, and the Mongol Empire was divided and plunged into civil war.

Meanwhile, Tolui's third son, Hulagu, who had been the commander-in-chief of the Western Expeditionary Forces, remained in Iran and established the Ilkhanate, an independent government that controlled Western Asia. However, the Ilkhanate came into conflict with Berke, the younger brother of Batu who succeeded the Golden Horde, over control of the steppes of the South Caucasus, resulting in the Berke-Hulegu War.

In addition, Kaidu (? - 1301), the son of Kashin, the fifth son of Ogedei, the third son of Genghis Khan, was in conflict with Kublai Khan's Yuan Empire for over 30 years, establishing an independent kingdom in Central Asia and ensuring the independence of the Mongolian powers west of Central Asia from the imperial power. This series of actions by Kaidu is generally known as the "Kaidu Rebellion."

In 1264, Kublai Khan defeated Ariq Boke, the youngest brother of Tolui, and won the War of Succession, becoming the fifth emperor in both name and reality. However, his direct rule only extended to the area east of the Mongolian Plateau, the Tianshan Uighur Kingdom and Tibet.

Kublai Khan, who was no longer able to invade West Asia, let alone Europe, established Yanjing (Beijing) as his provisional capital in 1264 and devoted himself to conquering East Asia, mainly by attacking the Southern Song Dynasty.

In 1266, Kublai Khan wrote the "Letter from the Emperor of the Great Mongol Empire" and sent an envoy to Japan, while in 1267 he began construction of Dadu (the official capital).

Kublai Khan's envoys ordered Goryeo King Wonjong to act as an intermediary, but although Goryeo guided them as far as Geoje Island on the southeastern coast of the Korean Peninsula, they complained about the dangers of the voyage and the disadvantages of maintaining relations with Japan, so the envoys returned home accompanied by Goryeo officials, and the mission ended in failure.

Kublai Khan sent envoys to Japan six times, but Hojo Tokimune (17 years old), who became the eighth regent in 1268, did not reply to any of the letters from Mongolia, nor did he adopt the draft reply prepared by the imperial court.

Meanwhile, the Kamakura shogunate, with Tokimune at its apex and assisted by the former regent Hojo Masamura, his brother-in-law Adachi Yasumori, Hojo Sanetoki, and Taira no Yoritsuna, had its vassals in the western provinces prepare for war and had shrines and temples offer prayers for the subjugation of foreign lands.

The reason why the Kamakura shogunate stubbornly refused to respond to the sovereign letter from Mongolia is thought to be because the shogunate did not have any legitimate diplomatic authority and did not want the Imperial Court in Kyoto to get involved.

The only person who could respond to the Yuan Emperor's letter on an equal footing was the Emperor of Japan himself, and the only role for Regent Tokimune, who was merely an advisor to the Shogun, was to repel Yuan attacks.

For Tokimune, who bore the hopes of the Hojo family on his shoulders, the greatest threat was the restoration of power to the Kyoto Imperial Court or to the Minamoto clan, and the threat of an invasion by the Mongols across the sea was of secondary importance.

In this situation, in 1274 (Bun'ei 11), the Yuan army finally invaded, resulting in the so-called Bun'ei War. After attacking Tsushima and Iki, 726-900 warships carrying 15,000-25,000 Mongol and Han troops and 5,300-8,000 Goryeo troops, for a total of 27,000-40,000 men, attacked the coast of Hizen.

When the situation on Tsushima and Iki was conveyed to Dazaifu, urgent messages were sent from Dazaifu to Kyoto and Kamakura. After a fierce battle, the Kyushu retainers (so called Gokenin) who had gathered in Dazaifu barely managed to stop the Mongol army from advancing inland, and with the help of a typhoon, the Mongol army was forced to retreat.

The following year, Mongol envoys led by Dushìzhong(杜世忠) arrived in Japan and demanded surrender, and Tokimune, who met them in Kamakura, executed them over the objections of Hojo Yoshimasa, the lieutenant (the assistant to the regent). Hojo Yoshimasa protested and became a monk, leaving the lieutenant position vacant until 1283. Thereafter, Mongol envoys led by Zhou Fu(周福), who arrived in Japan in 1279, were also executed in Dazaifu. The Kamakura shogunate initially ordered the dispatch of troops to Goryeo, but after considering military expenses, the order was cancelled and instead focused on strengthening national defense, such as building stone walls along the coast of Hakata Bay.

Zen master Mugaku Sogen(無学祖元), who was invited by Hojo Tokimune to come to Japan after the death of Zen Master Rankei Doryu(蘭溪道隆), the founder of Kamakura's Kenchoji Temple(建長寺), predicted a second Mongol invasion one month before the outbreak of the Koan Invasion (弘安の役1281), scolded Tokimune, saying, "Do not be troubled and do not be led astray but go straight."

Zen Master Sogen, who lived at both Kencho-ji Temple and Engaku-ji Temple in Kamakura and influenced many Kamakura warriors, was born in Yin County(鄞県), Qingyuan Prefecture (慶元府present-day Ningbo Special District, Zhejiang Province) in the second year of the Baoqing(宝慶) era (1226) during the Southern Song Dynasty in China. In the first year of the Jiaxi(嘉熙) era (1237), he became a monk under Beihan Jujian(北礀居簡) of Jingci Temple(浄慈寺) in Lin'an Prefecture(臨安府), and studied under Master Wuzhun(無準) of Jingshan Temple(径山寺), inheriting his teachings. When the Yuan army invaded, they fled from Zhenrusi(真如寺) Temple in Taizhou (台州present-day Zhejiang Province) to Nengren Temple(能仁寺) in Wenzhou(温州), but the temple was surrounded by the Yuan army. All the other monks fled, but Zen Master Mugakusogen(無学祖元) was the only one sitting at the centre of the meditation hall, calm and collected in a state of deep meditation(禅定三昧). Then, a Yuan soldier put a sword to Zen Master Sogen's neck and ordered him to "stand up." Zen Master Sogen rose to his feet calmly without the slightest fuss, drew a circle with his whisk, and recited the following verse:

－－－　－－－　－－－

乾坤無地卓孤筇 且喜人空法亦空 珍重大元三尺剣 電光影裏春斬風《仏光国師語録拾遺》

Guqiong(孤筇) is a type of bamboo that grows in the Sichuan region and is used as a substitute for a shakujo(錫杖), and refers to Zen Master Sogen himself. In other words, there is no room for Sogen in the universe, and there is no place for him to stand. Fortunately, people are vanity, and even Buddha's teachings are vanity. Daigen(大元) is the name of the Yuan Dynasty. How magnificent is the three-foot sword of the Yuan soldier. It will flash like lightning and cut off my neck like a spring breeze.

"I did a comprehensive study to seek the real universe, and finally got the answer.

That is to say, all is vanity. People are vanity, and even Buddha's teachings are vanity.

Now, I am spiritually awakened, and so, even if you want to kill me with your huge sword,

I don’t mind. I already know that I am vanity. This means when you swing your sword, you will

just cut through a spring wind."

－－－　－－－　－－－

The Yuan soldier was so impressed that he retreated without doing anything. This story proves the courage of Zen Master Sogen to overcome any great difficulty, but it also shows that Yuan soldier, who understood this verse and recognized the greatness of Zen Master Sogen, was no ordinary person.

Meanwhile, Sesson Yubai (雪村友梅1290-1347), who had trained at Kenchoji Temple(建長寺) in Kamakura, received the precepts at Mount Hiei(比叡山), and entered the Kenninji Temple(建仁寺) in Kyoto, crossed the sea at the age of 18 in 1307 to travel to the Yuan Dynasty, where he visited various masters around Dadu (Beijing) and trained under them, but was arrested and nearly executed on suspicion of espionage. However, when Sesson Yubai recited the Linjin Ge(臨刃偈) of Zen Master Sogen(祖元) in front of an executioner on the spur of the moment, the executioner was so impressed that he withheld the execution. In other words, it seems that even ordinary soldiers and executioners in the Yuan Dynasty were capable of understanding and admiring the Linjin Ge.

Not only did the Mongol Empire have deep ties with Nestorian Christianity from its inception, but all of its successive khans, beginning with Genghis Khan, relied on Zen monks as their close aides.

Yelu Chucai(耶律楚材1190-1244), a descendant of a Liao (遼Khitan契丹) clan, deeply devoted to Zen Buddhism and known as Zhanran Jushi(湛然居士), served as the Vice Director in the Left and Right Office(左右司員外郎) when Jin's Zhongdu (present-day Beijing) fell to the Mongol invasion. He was of good family background, tall and long haired, had a dignified demeanor, and was knowledgeable in astronomy and divination, so he caught the eye of Genghis Khan, who summoned him to serve as his aide. After Genghis' death, when the Kurultai were in a quandary over who would succeed Genghis, he is said to have contributed greatly to Ogedei's accession to the throne, advocating that Genghis's wishes be respected and that Ogedei should be appointed. After Ogedei ascended to the throne, he served as a Chinese language scribe (bichikchi) and became a senior official in the secretariat known as Zhongshu Sheng(中書省) in Chinese historical documents, and was involved in governing northern China (the Hitai region) under the former Jin dynasty. He devised a system to designate families whose occupation was Confucianism as "Ruhu(儒戸)", and in exchange for reduced taxes, they were made to study Confucianism and perform rituals, thus creating a source of practical bureaucrats. Following the example of successive Chinese dynasties, Ögedei protected the descendants of Confucius, which is also said to have been suggested by Chu Cai. However, in Ögedei's later years, a class of Muslim financial bureaucrats from Central Asia who advocated the introduction of a West Asian style head tax system, which taxes people on a per capita basis, came to prominence and began to interfere in Chinese administration, coming into conflict with the faction led by Chu Cai and others who wanted to maintain the traditional Chinese system of governance. In the end, it was simply easier to secure income by leaving it to the West Asian financial bureaucrats, so the Mongols began to favor them, and Chu Cai and his associates lost their trust.

According to the English Wikipedia, the most prominent, and arguably most influential, component of Kublai Khan's early life was his study and a strong attraction to contemporary Han culture. Kublai invited Haiyun, the leading Buddhist monk in northern China, to his ordo in Mongolia. Haiyun also introduced Kublai to the formerly Taoism, and at the time Buddhist monk, Liu Bingzhong. Liu was a painter, calligrapher, poet, and mathematician, and he became Kublai's advisor when Haiyun returned to his temple in modern Beijing.

Kublai Khan and the Yuan dynasty clearly favored Buddhism, while his counterparts in the Chagatai Khanate, the Golden Horde, and the Ilkhanate later converted to Islam at various times in history – Berke of the Golden Horde being the only Muslim during Kublai's era, However, his successor did not convert to Islam.

On May 3, 1281 (the 4th year of the Koan era, the 18th year of the Zhiyuan era), 900 warships carrying approximately 40,000 to 56,989 troops from the Eastern Army, mainly comprised of Yuan and Goryeo troops, set sail from Happo on the Korean Peninsula for Japan after being reviewed by King Chungnyeol of Goryeo.

In addition, 3,500 warships carrying approximately 100,000 troops from the Jiangnan army(江南軍), mainly composed of the former Southern Song army, set sail from Qingyuan (慶元Mingzhou明州), Dinghai(定海), and other places in mid-June of the same year.

The Eastern Route Army and the Jiangnan Army totaled 4,400 warships and 140,000 to 156,989 soldiers, and fought fierce battles with the Japanese forces on Iki Island and Takashima Island, but many of their warships were sunk or damaged in the typhoon that hit in the middle of the night of July 30th, causing them to retreat without landing on the Kyushu mainland. This was about three months after the Eastern Route Army set sail for Japan, and about two months after they entered Hakata Bay and began fighting.

Although he had repelled two attacks by the Mongol army, Tokimune was faced with difficult issues, such as the issue of rewards for his vassals and the need to strengthen national defense against further attacks by the Mongol army amid financial difficulties. Due to poor health, he became a monk on April 4, 1284 (Kōan 7), and died on the same day at the age of 34 according to the Japanese age reckoning system(32 in actual years). He was buried at Zuikakusan Engakuji Temple in Yamanouchi, Kamakura.

After five years of civil war had subsided, Kublai Khan planned a third expedition to Japan, but he died in 1294 (2nd year of Einin, 31st year of Zhiyuan). As a result, the shipbuilding plan in Goryeo was halted, and the plan to invade Japan was also called off.

When the Jiangzhe Province Pingzhang Governor Yestar (也早答兒) suggested a third invasion of Japan to Kublai Khan's successor, the sixth emperor Temur Khan, he rejected the suggestion, saying, "Now is not the time. I will consider it at my leisure." After that, no plans to invade Japan were ever made in the Yuan dynasty.

Temür Khan entrusted the official letter to Issan Ichinei(一山一寧), a monk from Fuda Zenji Temple(補陀禅寺), and sent him to Japan as a chief envoy.

The 9th regent, Hojo Sadatoki(北条貞時), escorted the envoy to Kamakura and detained him at Shuzenji Temple(修禅寺) in Izu(伊豆). Issan Ichinei was subsequently treated with great respect as a high-ranking monk, and served as the abbot of Kenchoji Temple(建長寺). He was also appointed third abbot of Nanzenji Temple(南禅寺) in Kyoto at the invitation of Emperor Emeritus Go-Uda(後宇多上皇), and died in Japan in 1317 (1st year of Bunpo, 4th year of En'yu).

According to the dialectic of the Gospel of John,

How then can a man possess eternal life?

When he said, "You are Huichao," Zen Master Fayan thrusted vivid Self in Huichao in front of his eyes.