Ii Naomasa

Who They Were

Ii Naomasa (井伊直政, いい なおまさ) was a samurai general and daimyo who served Tokugawa Ieyasu, the warlord who unified Japan and became shōgun. He was born on March 4, 1561, in Tōtōmi Province, and died on March 24, 1602, in Edo. His life spanned the Muromachi period (1336–1573), and he was born in the fourth year of the Eiroku era (永禄).

Naomasa came from the Ii clan, a family with deep roots in Tōtōmi. His father was Ii Naochika, and his mother was Hiyo Okuyama. After his father's death, Naomasa led the clan, succeeding the previous head, Ii Naotora. He married Tobai-in, the daughter of Matsudaira Yasuchika and the adopted daughter of Tokugawa Ieyasu. This marriage tied him directly to the Tokugawa household.

Life and Career

Naomasa joined the Tokugawa ranks in the mid-1570s. He rose quickly through the ranks, distinguishing himself as a capable and aggressive commander. His reputation grew markedly after the Battle of Komaki and Nagakute in 1584, where his performance earned him recognition as one of the Four Guardians of the Tokugawa, alongside Honda Tadakatsu, Sakakibara Yasumasa, and Sakai Tadatsugu. These four men were Ieyasu's most trusted and formidable generals.

Naomasa's military career peaked at the Battle of Sekigahara in 1600, the decisive confrontation that cemented Tokugawa supremacy over Japan. Following the battle, Ieyasu rewarded Naomasa with a sizable holding in Ōmi Province. This made him a daimyo in his own right, with substantial territory and income. He also held the office of Hyōbu-daifū, a post within the imperial court's ministry system, which gave him formal rank and prestige beyond his military role.

One of Naomasa's most distinctive traits was his command of elite troops known as the Red Guards (赤備え, akazonae). These soldiers wore red-lacquered armour and had formerly served the Takeda clan, a rival house that Tokugawa Ieyasu had destroyed. By taking over these veterans, Naomasa inherited both their fighting skill and their fearsome reputation. The red units became a signature of his command and a psychological weapon on the battlefield.

Why They Matter

Naomasa matters because he was one of the core military figures who made Tokugawa Ieyasu's rise possible. The Four Guardians were not just bodyguards; they were field commanders who won the battles that secured Ieyasu's position. Naomasa's role at Komaki and Nagakute and later at Sekigahara placed him at the centre of the most important military events of the late Sengoku period.

His adoption of the Takeda-style Red Guards also had lasting significance. The Takeda clan was renowned for its cavalry and aggressive tactics, and by absorbing their elite units, Naomasa preserved a fighting tradition that might otherwise have vanished. This made him a bridge between two great military houses, and it gave the Tokugawa forces a formidable offensive arm.

Naomasa's marriage to Ieyasu's adopted daughter further cemented his importance. He was not merely a hired general but a family member, bound by loyalty and blood to the Tokugawa cause. His early death in 1602, just two years after Sekigahara, cut short a career that might have made him even more powerful, but his sons carried on the Ii name and its legacy.

The Name in Japanese

The name is written 井伊直政.

• Kana reading: いい なおまさ
• Romaji: Ii Naomasa

The family name is 井伊 (Ii). It consists of two characters:

• 井 (い, i): meaning "well" or "water well." This character depicts a well frame and is also a common element in place names.
• 伊 (い, i): meaning "that one" or "this." It is often used phonetically in names and place names, particularly in the old province of Ise. In this name, it serves mainly to extend the sound of the first character.

The given name is 直政 (Naomasa). It also consists of two characters:

• 直 (なお, nao): meaning "straight," "direct," or "honest." This character carries strong connotations of integrity and straightforwardness, values prized among samurai.
• 政 (まさ, masa): meaning "government," "politics," or "rule." This character appears frequently in the names of daimyo and officials, signalling authority and administrative power.

Together, the name evokes a sense of upright governance, fitting for a man who served as a general and daimyo under the Tokugawa shogunate.

Legacy

Naomasa's legacy survived through his sons. His children included Ii Naotaka and Ii Naokatsu, both of whom carried on the Ii clan's service to the Tokugawa. The family continued to hold high rank and influence for generations, and the Ii name remained prominent in Japanese history long after Naomasa's death.

The Red Guards he commanded became a lasting symbol of elite samurai warfare. The image of red-armoured cavalry charging into battle was so striking that later commanders, including those outside the Ii clan, adopted the akazonae style to project the same fearsome image. In this way, Naomasa's military innovation outlived him.

His tomb and memorial sites in what is now Shizuoka Prefecture and Tokyo preserve his memory. For students of Japanese history, Naomasa stands as a model of the Sengoku-era general: loyal, aggressive, and rewarded with land and title for his service. His career illustrates how the Tokugawa shogunate was built not by Ieyasu alone, but by a network of capable commanders bound to him by marriage, duty, and shared victory.