Matsumoto Castle, formerly called “Fukashi Castle”, was a branch castle of the Ogasawara family during the middle ages. By that time there was already a marketplace on the east side of the secondary citadel, but the entire west side consisted of swampland, with the full-scale construction of the present structure beginning in the 1580s. The Ishikawa family, which entered this area as daimyo in the service of the Toyotomi family, promoted general urban planning, including that for both the casle and the surrounding castletown. The donjon is believed to have been built between 1593 and 1594, during the time of Lord Yasunaga, the second-generation Ishikawa daimyo.
The castle grounds were surrounded by the triple moat and ramparts, with the inner citadel and secondary citadel as the retrenchment and the tertiary citadel as the outer fortification, covering a total area of approximately 390,000m2. Within the retrenchment were the facilities of the fiefdom and its lord, including the donjon, the lord's residence and storehouses. In the outer fortification were located the homes of the elite class of samurai which made up the personal guard for the lord of Matsumoto Castle. An earthen wall was constructed atop the complete 3.5-km length of the ramparts, which were surrounded entirely in front by the moat. The only means of entrance into the castle were through mighty gated called Masugata and Umadashi.
The castletown was developed along the Zenkoji Road, which runs from south to norht through the town. On the east side of the town is a district of Buddhist temples and Shinto shrines. Many of the streets in the castletown have intersections which are L-shaped and T-shaped, with only few crossroads. The residential districts of the samurai and the merchants were strictly separated. The residential district of the samurai classes was divided into two parts by a gate. The inner part was for the homes of the middle-class samurai, and the outer part for the homes of the lower class samurai. The merchants' quarters consisted of three different areas: those made up of three neighbourhoods on the main street, ten neigbourhoods on the byroads, and 24 narrow alleyways. Each merchant lived in that area which had been set aside for hos own social ranking and / or occupation