江戸城外堀 The History of Edo Castle Outer Moat 江戸城は、本丸・二の丸・三の丸・西の丸・北の丸・吹上からなる内郭を内堀が囲み、その表門が大手門でした。外堀は、雉子橋門から時計回りに、一橋門、神田橋門、常盤橋門など諸門をめぐり、呉服橋門から虎ノ門、溜池から四谷門、市谷門、牛込門を経て、現在の神田川に入り、小石川門から浅草門で、隅田川に至る堀でした。外堀工事は、1606(慶長11)年に雉子橋から溜池までの堀を構築後、1618(元和4)年に駿河台が掘削されて平川(現日本橋川)の流路に付け替えられ、神田川が誕生しました。この工事で、平川は堀留橋で締め切られ、独立した堀となりました。 1636(寛永13)年には、天下普請で外堀が構築され、江戸の総構が完成します。この工事は、雉子橋から虎ノ門に至る外堀の総石垣化と枡形築造を前田・細川・池田・黒田家など西国外様大名(石垣方六組)、牛込土橋から赤坂土橋にかけての外堀掘削と土塁の構築を東国大名(堀方七組)が行いました。 その後も幕府は、外堀を維持するために大名の手伝普請による堀さらいをしました。牛込~市谷間の堀は、市谷~四谷間より水位が下がり、土砂が堆積し、蓮が繁ったため、普請奉行の管理下で頻繁にさらいが行われました。また、町人にも堀にゴミを捨てないよう町触も出され、外堀の維持・管理が行われました。
Edo Castle’s inner hull was comprised of six citadels: the main, second, third, western, northern, and fukiage citadels. The entire inner hull was encircled by an internal moat and Ōte-mon Gate served as its main entrance. The Castle’s outer moat originated at Kijibashi-mon Gate and passed, in clockwise direction, through Hitotsubashi-mon, Kandabashi-mon, Tokiwa-bashi-mon, Gofukubashi-mon, and Torano-mon Gates. It then extended from Castle reservoir through Yotsuya-mon, Ichigaya-mon, and Ushigome-mon Gates before ultimately flowing into the present-day Kanda River. From there. it served as a canal, which passed through Koishikawa-mon and Asakusa-mon Gates and ultimately converged with the Sumida River. The outer moat’s development began in 1606 with the construction of a canal from Kiji-bashi Bridge to the Castle reservoir. The second stage in its evolution came in 1618, when portions of the Kanda Plateau were removed and the canal was redirected towards the Hira River. That process gave birth to the Kanda River and transformed the Hira River, which was closed off at Horidome-bashi Bridge, into an independent canal. The outer moat was finally completed in 1636, when feudal lords from eastern and western Japan were mobilized to construct its remaining portions. Specifically, western domainal lords, including the Maeda, Hosokawa, Ikeda, and Kuroda Houses, were ordered to supervise the construction of stone walls and the square masugata enclosures used to protect the castle gates along the section of outer moat between Kiji-bashi Bridge and Torano-mon Gate. In constrast, domainal lords from eastern Japan were order to dig a canal between Ushigome-bashi and Akasaka-bashi Bridges and construct earthen fortifications. In order to maintain the outer moat, the Tokugawa shogunate mobilized domainal lords from around the country to dredge it. In particular, the section of the moat between Ushigome and Ichigaya required frequent dredging because the water level often receded, resulting in the accumulation of silt on the moat floor and the development of water lilies on its surface. Such dredging projects were carried out under the supervision of the shogunate’s Governor of Construction. In addition, the city authori-ties attempted to keep the outer moat free of debris by issuing official proclamations banning the residents of commoner neigh-borhoods from disposing of garbage in the moat.
赤坂門:長崎大学附属図書館蔵
Akasaka-mon Gate: “Photo Tokyo Past and Present” Hiroshi Nozawa
喰違:『絵本江戸土産』国立国会図書館蔵
Kuichigai-mon Gate: “Edo Souvenir in Pictures” National Diet Library
そのほか:『旧江戸城写真帖』東京国立博物館蔵
Others: “Old Edo Castle Photo Collection” Tokyo National Museum
江戸城 The History of Edo Castle 江戸城は、平安時代末の江戸氏居館、室町時代の太田道灌、戦国時代の小田原北条氏の支城として受け継がれました。豊臣秀吉は、北条氏を滅ぼすと、徳川家康を関東に移封しました。1590(天正18)年、徳川家康は江戸城に入城し、江戸城と城下町の建設を始めました。家康入城時の江戸城には石垣はなく土塁のみで、日比谷も入り江で日本橋・京橋辺りも海面と同じ高さの湿地でした。 家康は、まず城内の寺を出し本丸を拡張し、城下町の武家地、町人地を整えました。次に、本丸の南の台地を削り西の丸を造成し、その残土で日比谷入り江を埋め立てました。1603(慶長8)年、幕府を開き実権を握った家康は、天下普請として、城と城下町建設に諸大名を動員しました。同じ年に、神田山を崩して日本橋南の地域を埋め立て、市街地の造成と日本橋の架橋を行い、翌年には日本橋を起点とする五街道を整備しました。1606(慶長11)年には二の丸・三の丸と城郭の整備、石垣築造を進め、翌年には天守が完成しました。なお、天守は1657(明暦3)年に大火で焼失した後、再建されませんでした。 1868(明治元)年、明治天皇が江戸城に入り皇居となり、1960(昭和35)年、江戸城内郭の堀が「江戸城跡」として国の特別史跡に指定されました。このほか、「江戸城外堀跡」と「常盤橋門跡」が史跡に、外桜田門、田安門、清水門とそれぞれの櫓門が重要文化財に指定されています。
Edo Castle’s origins can be traced to the establishment of the Edo Clan’s estate in the late-Heian period. During the Muromachi period, it served as the location of Ōta Dōkan’s branch castle. Entering the Warring States Period, it was controlled by the Hōjō Clan’s and served as the site of their branch castle. When Toyotomi Hideyoshi eradicated the Hōjō Clan in the late-sixteenth century, Tokugawa Ieyasu was sent to their former territory in the Kantō region. In 1590, leyasu assumed control of Edo Castle and initiated the Castle’s reconstruction and construction of the surrounding castle town. At the time, there were no stone walls on the Castle site. The only remaining features of the Hōjō Clan’s branch castle were its earthen fortifications. In addition, the Hibiya area was an inlet and the Nihonbashi and Kyōbashi areas were low-lying wetlands. leyasu began the reconstruction effort by removing temples from the site, expanding the Castle’s inner citadel, and supervising the construction of the city’s commoner districts and warrior estates. He then removed portions of the plateau immediately south of the inner citadel and constructed the western citadel. In addition, the inlet in Hibiya was filled in using the earth removed from the plateau. In 1603, leyasu, who had by then seized national political authority and established a tent government, mobilized domainal lords from the across the country to construct the remaining portions of Edo Castle and the surrounding city area. The same year, Kanda Hill was leveled and earth removed from the Hill was used to fill in the southern portions of the Nihonbashi area. The area was then developed and Nihon-bashi Bridge was constructed. The following year, an archipelago-wide network of five overland circuits originating from Nihon-bashi Bridge was established. In 1606, the second and third citadels and castle tower were constructed and work continued on the stone walls surrounding the Castle. By the following year, the Castle’s main keep was complete. In 1657, however, the Castle was destroyed by a fire and had to be reconstructed. In 1868, the Meiji emperor moved to Edo Castle and it came to serve as the imperial palace. In 1960, Edo Castle’s inner moat was classified as Edo Castle’s official ruins and designated a National Heritage Site. In addition, remaining portions of the Castle’s outer moat and the ruins of Tokiwabashi Gate received designation as Historical Landmarks. Lastly, the box-shaped, two-story gatehouses at Sakurada-mon, Tayasu-mon, and Shimizu-mon Gates were designated as Important National Treasures.