Heir to a long line of powerful feudal lords in the Tōhoku region, he went on to found the modern-day city of Sendai.

An outstanding tactician, he was made all the more iconic for his missing eye, as Masamune was often called dokuganryū (独眼竜), or the "One-Eyed Dragon of Ōshū".

Shortly after Masamune's succession in 1584, a Date retainer named Ōuchi Sadatsuna defected to the Ashina clan of the Aizu region.

Formerly amicable alliances were cast aside as he began to attack and conquer the lands of Sadatsuna's allies in pursuit, even those of his kin in Mutsu and Dewa Province.

The incident ended with Terumune and Yoshitsugu killed as the fleeing Nihonmatsu party clashed with the pursuing Date troops near the Abukuma River.

[6] The following year, Date Masamune once again attacked Nihonmatsu at Battle of Koriyama in 1588, The son of Hatakeyama Yoshitsugu set the castle on fire and fled to Aizu.

After defeating the Ashina clan, Masamune made Kurokawa Castle in Aizu domain his base of operations.

Expecting to be executed, Masamune, wearing his finest clothes and showing no fear, faced his angry overlord.

Toyotomi Hideyoshi reduced the size of his land holdings after his tardiness in coming to the Siege of Odawara against Hōjō Ujimasa.

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."

As someone who did not experience the Warring States period, Iemitsu had a fondness for hearing stories from the warlords who lived during that time, such as Masamune and Tachibana Muneshige.

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.

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.

Matsushima, for instance, a series of tiny islands, was praised for its beauty and serenity by the wandering haiku poet Matsuo Bashō.

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.

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.

[11] Like many figures of the Sengoku period, Date Masamune has been featured in literature, film, manga, anime, video games, and other media.

[25] In the video game series Samurai Warriors (Koei) Masamune Date is featured as a playable character.

He is also a prominent character in the Sengoku Basara series (Capcom), and has been featured in every major release, portrayed as a reckless, but astute general with a penchant for using humorous English verses, he is also notable for carrying six katanas, which he can equip as "dragon's claws", wielding them between his fingers, three in each hand.

In the popular Netflix miniseries Age of Samurai: Battle for Japan, Date Masamune is portrayed by actor Hideaki Itō.