Matsudaira Masachika

Who They Were

Matsudaira Masachika (松平昌親, まつだいら まさちか) was a Japanese samurai of the early to mid-Edo period, born on 31 May 1640 in Edo. He served as both the 5th and 7th daimyō of Fukui Domain, a major feudal holding in Echizen Province. His father was Matsudaira Tadamasa, and his spouse was Mori Man-hime (森万姫).

Masachika lived from 1640 to 1711, spanning the reigns of four Tokugawa shōguns. His lifetime fell entirely within the Edo period (1603–1868), a time of relative peace under Tokugawa rule. He was born in the 17th year of the Kan'ei era (寛永), a nengō, or era name, that ran from 1624 to 1644.

Life and Career

Masachika's career was unusual in that he held the same domain twice. He first became daimyō of Fukui Domain, then relinquished the position, and later returned to it. This double tenure made him both the 5th and 7th lord of the domain, a rare distinction among Edo-period daimyō.

The domain itself was one of the most prestigious in Japan. Fukui was held by a branch of the Matsudaira clan, the family name borne by the Tokugawa shōguns themselves. As a daimyō, Masachika was responsible for administering his domain's lands, collecting taxes, and maintaining order among his retainers and the peasant population.

His father, Matsudaira Tadamasa, had preceded him in the lordship, and Masachika's own son would later be referenced in connection with the family line. The succession pattern suggests a family deeply embedded in the upper ranks of the samurai class, with direct ties to the shōgun's house.

Beyond his administrative duties, Masachika is credited with a small but lasting linguistic act: he changed the spelling of the domain's name from 福居 to 福井. Both characters could be read as "Fukui," but the new spelling carried a different meaning, as discussed below.

Why They Matter

Masachika matters for two concrete reasons. First, his double tenure as daimyō illustrates the fluidity of succession in early Edo-period domains, where lords could step down, retire, or be reinstated depending on political circumstances. His case shows that daimyō status was not always a single, uninterrupted term of office.

Second, his decision to alter the spelling of "Fukui" from 福居 to 福井 had lasting consequences. The modern city of Fukui, the capital of Fukui Prefecture, uses the 福井 spelling he promoted. Every time the name appears on a map, a train station, or a government document, it reflects a choice made by a 17th-century daimyō.

His life also spans a pivotal stretch of the Edo period. Born in 1640, he came of age after the Tokugawa consolidation of power, and he died in 1711, just before the Genroku era's cultural flowering gave way to the reforms of the 18th century. His career belongs to the period when the shogunate's administrative structures were hardening into their mature form.

The Name in Japanese

The name 松平昌親 is read in Japanese as まつだいら まさちか, romanised as Matsudaira Masachika.

Character by character:

• 松 (まつ, matsu) — "pine tree." This is the first character of the Matsudaira surname, which the Tokugawa family also used before adopting the name Tokugawa. The pine is a symbol of longevity and resilience in Japanese culture.
• 平 (たいら, taira) — "flat" or "peace." Combined with 松, it forms 松平, Matsudaira. The character 平 also appears in the name of the Taira clan, one of the great warrior houses of earlier centuries.
• 昌 (まさ, masa) — "prosperous" or "flourishing." This is the first character of his given name, Masachika. It conveys a wish for the family's continued success.
• 親 (ちか, chika) — "close" or "intimate," as in a close relative. In names, it often carries the sense of closeness to one's kin or to the shōgun. Together, 昌親 (Masachika) suggests a person who brings prosperity through close bonds.

Note that the reading of 親 as chika is not the standard on-reading (しん, shin) or kun-reading (おや, oya). It is a nanori reading, a special pronunciation used only in personal names. This is common in Japanese given names, where characters take readings that do not appear in ordinary vocabulary.

The surname 松平 is also notable for its history. Before the Tokugawa family rose to power, they used this surname. When Tokugawa Ieyasu became shōgun, he granted the Matsudaira name to trusted branch families, including the lords of Fukui Domain. Thus, the name itself was a marker of prestige and proximity to the shōgun.

Legacy

Masachika's most visible legacy is the spelling of Fukui. The shift from 福居 to 福井 changed the second character from one meaning "to dwell" (居) to one meaning "well" or "water well" (井). The new spelling, 福井, can be read as "fortunate well," a more auspicious combination than the older "fortunate dwelling."

This change was not merely cosmetic. In the Edo period, domain names were official designations used in documents, maps, and communications with the shogunate. A daimyō's choice of characters carried weight, and Masachika's revision was adopted and retained. The modern city of Fukui and Fukui Prefecture both use his spelling.

His double tenure as daimyō also left a structural mark on the domain's history. The fact that he served twice suggests that the succession was not smooth, and that the domain's lordship passed through him on two separate occasions. This pattern of stepping down and returning was not uncommon among Edo-period daimyō, who sometimes retired to hand power to an heir and then resumed control if that heir died or proved incapable.

Masachika died on 23 October 1711, at the age of 71. His life bridged the early and middle Edo period, and his name remains attached to one of Japan's most enduring place-name spellings.