As the records of the Tokugawa clan reveal, the Edo Castle was not regarded as a vital branch-castle in the time of the Gohojo clan and its modest structure that was constructed in the 15th century remained; However, it should be noted that the foundations that would enable Edo to develop into the capital of eight provinces had already been laid.
確かに徳川氏の記録が伝えるように、後北条氏時代の江戸城は最重要な支城とまではみなされず城は15世紀の粗末なつくりのまま残されていたが、関八州の首府となりうる基礎はすでに存在していた。