The Tokugawa family, who ruled Japan for some 250 years until the mid-19th century, established the so-called "the Gosanke" three branch families in Nagoya, Wakayama and Mito. The best boy from each of the head family and these three families was to be appointed as a new shogun, a ruler of Japan. As they thought this system was not enough, however, the so-called "the Gosankyo" three secondary branch families were added later in the mid-18th century. These new families were the Tayasu-Tokugawa family, Shimizu-Tokugawa family and Hitotsubashi-Tokugawa family. Consequently, the number of the Tokugawa's families being eligible for the next shogun reached 7, counting the head family. 4 out of 7 families lived in Edo, present Tokyo. The head family lived in the main enclosure of Edo Castle, the Tayasu and Shimizu in the northern enclosure of the castle, present Kitano-maru Park. The pictures show the Tayasu-mon gate and Shimizu-mon gate. The first one was the main gate of Tayasu's mansion and the second one was the main gate of Shimizu's mansion, both of which were built early in the 17th century as the gates of Edo Castle. They are on the list of important cultural assets. Hitotsubashi's mansion stood out of the castle grounds and unfortunately nothing remains. The 15th shogun, the last shogun Tokugawa Yoshinobu, was from the Hitotsubashi-Tokugawa family though, the Tayasu and the Shimizu had never produced any shogun.
Licensed tour guide, travel consultant,