* Image is for illustrative purposes only.Nagurumi Castle
名胡桃城
Nagurumi Castle is a historic castle in Kantō dating from the Built 1579 (Tensho 7), abandoned 1590 (Tensho 18), whose lord was Sanada Masayuki.
Overview
Founding
Nagurumi Castle stands atop a cliff overlooking a tributary of the Tone River in Minakami, Tone District, Gunma Prefecture. Its origins trace to the Muromachi period, when the Nagurumi clan, said to be a branch of the Numata clan, built a residence on the site. In 1579 (Tensho 7), Takeda Katsuyori of Kai ordered his retainer Sanada Masayuki to construct a fortress adjacent to the Nagurumi residence as a forward base for seizing Numata territory from the rival Later Hojo clan.
A Base for the Numata Campaign
Sanada Masayuki, together with Ogawa Kayusai, lord of Ogawa Castle, first captured the Nagurumi residence and used it as a foothold to build Nagurumi Castle on the adjoining ground. From there he pursued the political subjugation of nearby Numata Castle and eventually succeeded in taking it. Although the castle functioned as a fortress for only about a decade, it played a critical role as the front line of Sanada control over the Numata region.
Structure and Defense
Nagurumi Castle follows a linear (rengaku) layout in which a horse-baffle (umadashi), the third, second, and main baileys, and the Sasa bailey are arranged in sequence. Steep cliffs flank both sides, forming a natural stronghold that could be defended effectively even by a small garrison.
Related Conflict — The Nagurumi Castle Incident and the Siege of Odawara
On November 3, 1589 (Tensho 17), Inomata Kuninori, a Hojo retainer serving as castellan of Numata, seized Nagurumi Castle from the Sanada clan. This "Nagurumi Castle Incident" was regarded as a unilateral violation of the Numata territorial ruling issued by Toyotomi Hideyoshi, and it became the direct pretext for Hideyoshi's campaign against the Later Hojo clan. In March 1590 (Tensho 18), Hideyoshi dispatched a massive army, and by July of that year the Later Hojo clan had fallen, effectively bringing the Sengoku period to a close.
Present Day
Following the campaign, the Numata territory was confirmed to the Sanada clan, and Nagurumi Castle, having fulfilled its purpose, was abandoned. Today it is preserved as a Gunma Prefectural Historic Site, with its linear bailey layout, horse-baffle, and dry moats surviving in good condition. It is also designated one of the Continuation Top 100 Japanese Castles.
Connection to Swords
Not applicable
Highlights
- Site of the Nagurumi Castle Incident
- Direct trigger of the Siege of Odawara
- Well-preserved linear bailey layout
- Designated Continuation Top 100 Japanese Castle
* Opening hours and admission fees are subject to change. Please check the official website before visiting.