Date Masamune As a legendary warrior and leader , Masamune is a character in a number of Japanese period dramas . He was played by Ken Watanabe in the popular 1987 NHK series " Dokuganryu Masamune . " Background . Date Masamune was the eldest son of Date Terumune , born in Yonezawa Castle ( in modern Yamagata Prefecture ) . At the age of 14 in 1581 Masamune led his first campaign , helping his father fight the Sōma family . In 1584 , at the age of 17 , Masamune succeeded his father , Terumune , who chose to retire from his position as daimyo . The Date family was founded in the early Kamakura period by Isa Tomomune , who originally came from the Isa district of Hitachi Province ( now Ibaraki Prefecture ) . The family took its name from the Date district ( now Fukushima Prefecture ) of Mutsu Province , which had been awarded to Isa Tomomune by Minamoto no Yoritomo , the first Kamakura shogun , for his assistance in the Genpei War ( 1180 – 85 ) and in Minamoto no Yoritomo ’ s struggle for power with his brother , Minamoto no Yoshitsune . Masamune ' s army was recognized by its black armor and golden headgear . Historical person . Masamune is known for a few things that made him stand out from other daimyo of the time . In particular , his famous crescent - moon - bearing helmet won him a fearsome reputation . As a child , smallpox robbed him of sight in his right eye , though it is unclear exactly how he lost the organ entirely . Some sources say he plucked out the eye himself when a senior member of the clan pointed out that an enemy could grab it in a fight . Others say that he had his trusted retainer Katakura Kojūrō gouge out the eye for him . Because of his missing eye , his own mother condemned him as unfit to take over as clan leader and began favoring his younger brother as heir . The Date clan had built alliances with neighboring clans through marriages over previous generations . However , there were many disputes over the lands during the 15th and 16th centuries . Shortly after Masamune ' s succession , a Date retainer named Ōuchi Sadatsuna defected to the Ashina clan of the Aizu region . Masamune declared war on the Ashina for this betrayal , but his army was halted by the Ashina general Inawashiro Morikuni , who forced Masamune to retire from the campaign . Masamune took control of Obama Castle after this . With the rise of Masamune , formerly amicable relationships were cast aside as he began to attack and conquer all of the surrounding lands , even those of his kin in Mutsu and Dewa Provinces . Shocked by his ruthlessness , a neighboring family , the Hatakeyama , desperately appealed to Date Terumune to rein in his son ' s military campaigns . Invited to dinner by the Hatakeyama , Terumune said that he was unable to control his son . In an unheard - of act of desperation , the family kidnapped Terumune and attempted to take him back with them . Masamune , who was out hunting , received word of the kidnapping . When he and his men closed in on the kidnappers as they were about to cross a river , Terumune ordered his son ' s men to kill all the enemies , even at the cost of his own life . Masamune ' s men did as they were told and killed everyone , including Terumune . Masamune continued the war and tortured and killed the families of his father ' s kidnappers . After defeating the Ashina in 1589 , he made the Aizu domain his base of operations . Meanwhile , his relationship with his mother , Yoshihime , continued to deteriorate . Yoshihime insisted Masamune resign the succession to her second son , Kojiro . According to some historians , she tried to poison him one night while serving him dinner . Masamune consequently killed his own brother in order to come to power . After this tragedy , his mother fled to her brother ' s home , the Mogami clan . In 1590 , Toyotomi Hideyoshi seized Odawara Castle and compelled the Tōhoku region daimyos to participate in the campaign . Although Masamune refused Hideyoshi ' s demands at first , he had no real choice in the matter since Hideyoshi was the virtual ruler of Japan . Masamune still delayed , infuriating Hideyoshi . Expecting to be executed , Masamune , wearing his finest clothes and showing no fear , faced his angry overlord . Not wanting further trouble , Hideyoshi spared his life , saying that " He could be of some use " . After serving Hideyoshi for a time , he was given Iwatesawa castle and the surrounding lands as his home domain . Masamune moved there in 1591 , rebuilt the castle , renamed it Iwadeyama , and encouraged the growth of a town at its base . Masamune stayed at Iwadeyama for 13 years and turned the region into a major political and economic center . He and his men served with distinction in the Korean invasions under Hideyoshi and , after Hideyoshi ' s death , he began to support Tokugawa Ieyasu — apparently at the advice of Katakura Kojūrō . Tokugawa Ieyasu awarded Masamune the lordship of the huge and profitable Sendai Domain , which made Masamune one of Japan ’ s most powerful daimyo . Tokugawa had promised Masamune a one million koku domain , but , even after substantial improvements were made , the land only produced 640 , 000 koku , most of which was used to feed the Edo region . In 1604 , Masamune , accompanied by 52 , 000 vassals and their families , moved to what was then the small fishing village of Sendai . He left his fourth son , Date Muneyasu , to rule Iwadeyama . Masamune would turn Sendai into a large and prosperous city . Although Masamune was a patron of the arts and sympathized with foreign causes , he was also an aggressive and ambitious daimyo . When he first took over the Date clan , he suffered a few major defeats from powerful and influential clans such as the Ashina . These defeats were arguably caused by recklessness on Masamune ' s part . Being a major power in northern Japan , Masamune was naturally viewed with suspicion , as any potential rival would be viewed . Toyotomi Hideyoshi reduced the size of his land holdings after his tardiness in coming to the Siege of Odawara against Hōjō Ujimasa . Later in his life , Tokugawa Ieyasu increased the size of his lands again , but was constantly suspicious of Masamune and his policies . Although Tokugawa Ieyasu and other Date allies were always suspicious of him , Date Masamune for the most part served the Tokugawa and Toyotomi loyally . He took part in Hideyoshi ' s campaigns in Korea , and in the Osaka campaigns . When Tokugawa Ieyasu was on his deathbed , Masamune visited him and read him a piece of Zen poetry . Masamune was highly respected for his ethics ; a still - quoted aphorism is , " " Rectitude carried to excess hardens into stiffness ; benevolence indulged beyond measure sinks into weakness . " " Patron of culture and Christianity . Masamune expanded trade in the otherwise remote , backwater Tōhoku region . Although initially faced with attacks by hostile clans , he managed to overcome them after a few defeats and eventually ruled one of the largest fiefdoms of the later Tokugawa shogunate . He built many palaces and worked on many projects to beautify the region . He is also known to have encouraged foreigners to come to his land . Even though he funded and promoted an envoy to establish relations with the Pope in Rome , he was likely motivated at least in part by a desire for foreign technology , similar to that of other lords , such as Oda Nobunaga . Further , once Tokugawa Ieyasu outlawed Christianity , Masamune reversed his position , and though disliking it , let Ieyasu persecute Christians in his domain . For 270 years , Tōhoku remained a place of tourism , trade and prosperity . Matsushima , for instance , a series of tiny islands , was praised for its beauty and serenity by the wandering haiku poet Matsuo Bashō . He showed sympathy for Christian missionaries and traders in Japan . In addition to allowing them to come and preach in his province , he also released the prisoner and missionary Padre Sotelo from the hands of Tokugawa Ieyasu . Date Masamune allowed Sotelo as well as other missionaries to practice their religion and win converts in Tōhoku . Masamune ' s greatest achievement was funding and backing one of Japan ' s few journeys of far - flung diplomacy and exploration in this period . He ordered the building of the exploration ship " Date Maru " or " San Juan Bautista " , using foreign ( European ) ship - building techniques . He sent one of his retainers , Hasekura Tsunenaga , Sotelo , and an embassy numbering 180 on a successful voyage to establish relations with the Pope in Rome . This expedition visited such places as the Philippines , Mexico , Spain and Rome , making it the first Japanese voyage to sail around the world . Previously , Japanese lords had never funded this sort of venture , so it was probably the first successful voyage . At least five members of the expedition stayed in Coria ( Seville ) of Spain to avoid the persecution of Christians in Japan . 600 of their descendants , with the surname Japón ( Japan ) , are now living in Spain . When the Tokugawa government banned Christianity , Masamune had to obey the law . However , some sources suggest that Masamune ' s eldest daughter , Iroha , was a Christian . Popular culture . In popular culture , Date Masamune is a playable character in these videogames : Koei ' s " Samurai Warriors " series , " Pokémon Conquest " ( " Pokémon + Nobunaga ' s Ambition in Japan " ) , with his partner Pokémon being Rufflet and Braviary , and Capcom ' s " Sengoku Basara " videogame series , as well as the anime " " . In addition , professional wrestling promotion Osaka Pro Wrestling features two wrestlers using the ring name s Masamune and Hideyoshi , who together form the tag team " Sengoku " .