Musashi Province (武蔵の国, Musashi no kuni) was a province of Japan, which today comprises Tokyo Metropolis, most of Saitama Prefecture and part of Kanagawa Prefecture. It was sometimes called Bushū (武州). The province encompassed Kawasaki and Yokohama. Musashi bordered on Kai, Kōzuke, Sagami, Shimōsa, and Shimotsuke Provinces.
Musashi was the largest province in the Kantō region.
The name Musashi, recorded in early records as 牟射志 muzasi, has been conjectured to be of Ainu origin. It has no apparent meaning in Japanese, but mun-sar-i or mun-sar-ihi (weed-marsh-POSS) is a hypothetical Ainu form that would mean "marsh/wetland of (i.e. belonging to) weeds/inedible or otherwise useless plants," and Musashi sits in the middle of the Kantō Plain.
Musashi had its ancient capital in modern Fuchū, Tokyo and its provincial temple in what is now Kokubunji, Tokyo. By the Sengoku period, the main city was Edo, which became the dominant city of eastern Japan. Edo Castle was the headquarters of Tokugawa Ieyasu before the Battle of Sekigahara and became the dominant city of Japan during the Edo period, being renamed Tokyo during the Meiji Restoration.
Hikawa jinja was designated as the chief Shinto shrine (ichinomiya) of the province; and there are many branch shrines.
The former province gave its name to the battleship of the Second World War Musashi.
July 18, 707 (Keiun 4, 15th day of the 6th month): Empress Genmei is enthroned at the age of 48.
707 (Keiun 4): Copper was reported to have been found in Musashi province in the region which includes modern day Tokyo.
708 (Keiun 5): The era name was about to be changed to mark the accession of Empress Gemmei; but the choice of Wadō as the new nengō for this new reign became a way to mark the welcome discovery of copper in the Chichibu District of what is now Saitama Prefecture. The Japanese word for copper is dō (銅); and since this was indigenous copper, the "wa" (the ancient Chinese term for Japan) could be combined with the "dō" (copper) to create a new composite term—"wadō"—meaning "Japanese copper".
May 5, 708 (Wadō 1, 11th day of the 4th month): A sample of the newly discovered Musashi copper was presented in Gemmei's Court where it was formally acknowledged as Japanese copper. The Wadō era is famous for the first Japanese coin (和同開珎, wadokaiho or wadokaichin).
1590 (Tenshō 18): Siege of Odawara. Iwatsuki Domain and Oshi Domain founded in Musashi Province.
Musashi Province had 21 districts, added one after.
Saitama Prefecture
Chichibu District (秩父郡)
Hanzawa District (榛沢郡) - merged into Ōsato District (along with Hatara and Obusama Districts) on March 29, 1896
Hatara District (幡羅郡) - merged into Ōsato District (along with Hanzawa and Obusama Districts) on March 29, 1896
Hiki District (比企郡) - absorbed Yokomi District on March 29, 1896
Iruma District (入間郡) - merged into Koma District on March 29, 1896
Kami District (賀美郡, 加美郡) - merged into Kodama District (along with Naka District) on March 29, 1896
Kodama District (児玉郡) - absorbed Kami and Naka Districts on March 29, 1896
Koma District (高麗郡) - merged into Iruma District on March 29, 1896
Naka District (那珂郡) - merged into Kodama District (along with Kami District) on March 29, 1896
Niikura District (新座郡, 新倉郡, 新羅郡) - merged into Kitaadachi District on March 29, 1896
Obusuma District (男衾郡) - merged into Ōsato District (along with Hanzawa and Hatara Districts) on March 29, 1896
Ōsato District (大里郡) - absorbed Hanzawa, Hatara and Obusama Districts on March 29, 1896
Saitama District (埼玉郡)
Kitasaitama District (埼玉郡) - dissolved
Minamisaitama District (埼玉郡)
Yokomi District (横見郡) - merged into Hiki District on March 29, 1896
Tokyo Prefecture
Ebara District (荏原郡) - dissolved
Tama District (多摩郡, 多麻郡, 多磨郡)
Higashitama District (東多摩郡) - merged with Minamitoshima District to become Toyotama District (豊多摩郡) on April 1, 1896
Kitatama District (北多摩郡) - was part of Kanagawa Prefecture in 1878 until being transferred to Tokyo Prefecture in 1893; now dissolved
Minamitama District (南多摩郡) - was part of Kanagawa Prefecture in 1878 until being transferred to Tokyo Prefecture in 1893; now dissolved
Nishitama District (西多摩郡) - was part of Kanagawa Prefecture in 1878 until being transferred to Tokyo Prefecture in 1893
Toshima District (豊嶋郡)
Kitatoshima District (北豊島郡) - dissolved
Minamitoshima District (南豊島郡) - merged with Higashitama District to become Toyotama District on April 1, 1896
Kanagawa Prefecture
Kuraki District (久良岐郡) - dissolved
Tachibana District (橘樹郡) - dissolved
Tsuzuki District (都筑郡) - dissolved
Mixed
Adachi District (足立郡)
Kitaadachi District (Saitama) (北足立郡) - absorbed Niikura District on March 29, 1896
Minamiadachi District (Tokyo) (南足立郡) - merged into the city of Tokyo on October 1, 1932
Katsushika District (葛飾郡) — Transfer from Shimōsa Province in 1683 (some say 1622–1643) for the river improvement of Naka River.
Kitakatsushika District (Saitama) (北葛飾郡) - absorbed Nakakatsushika District (Shimōsa, Saitama) on March 29, 1896
Minamikatsushika District (Tokyo) (南葛飾郡) - merged into the city of Tokyo on October 1, 1932
