Edo Castle is one of the grandest and most elaborate castles in Japan. The grounds of the castle (inside the inner moat) cover an oval-shaped area that is over 2 km from north to south and almost 1.5 km from east to west. Inside the moat are a variety of residences owned by the most important daimyo and for distant relatives of the shogun, living quarters for the thousands of servants and castle officials, and extensive gardens with beautiful flowering trees, ponds and walkways. At the center of the entire complex is the Shogun's own residence.
However, Edo Castle was not always so large and grand. When it was first built, in 1457, it was just a small fortress on top of a hill surrounded by marshes. The castle was built by Ota Dokan, a small local ruler who served the daimyo of the Hojo family. Ota Dokan chose a fine site for his castle. The hill on which it was built was surrounded on three sides by the marshes and swamps at the mouth of the Sumida river, and by Edo Bay. After his laborers finished digging a moat on the fourth side to cut it off from the hilly Yamanote district, the castle was entirely surrounded by water and swampy land, making it nearly impossible to attack.
In 1589, Hojo Ujimasa was defeated by Toyotomi Hideyoshi in the seige of Odawara, and Hideyoshi confiscated all the lands that formerly belonged to the Hojo family. Hideyoshi wanted to reward Tokugawa Ieyasu for his help in defeating the Hojo, but since Ieyasu was one of the most powerful daimyo in the country, Hideyoshi didn't want to reward him TOO much, lest he become even stronger than Hideyoshi. Eventually, Hideyoshi called Ieyasu to his castle in Osaka and offered to give him all the land formerly owned by the Hojo family, provided he gave up the land he already owned. The new lands Ieyasu was offered were much larger, but they were farther away from the capital city of Kyoto. Hideyoshi figured that if Ieyasu was far away, he couldn't interfere as much in the way Hideyoshi ran the country.
Ieyasu was not entirely happy with this "reward", but he decided to make the best of it. He had been to Ota Dokan's castle before, and knew that it could be made into an impregnable fortress with a little bit of work. So in 1590, he and all his family, his retainers and all the samurai who served him moved to Edo. Immediately, he and his men set to work rebuilding the castle, constructing huge walls of stone and wide moats, and reinforcing the defenses around it.
When they first arrived in Edo, Ieyasu and his men found the castle very run-down, and the town of Edo, which was next to the castle, consisted of two tiny rows of houses on the shore of the bay. The first thing they did was to level the other nearby hills, so that the castle would occupy the only high ground in the area. Kanda hill was entirely removed and the dirt excavated from the hill was used to fill in the shallow mud flats on the shore of the bay. Soon, a wide stretch of marshes and mud flats to the east of the castle had been converted to dry land, and this is where Ieyasu's soldiers and subordinates built their homes.
In 1603, Ieyasu defeated all other rival daimyo in the country in a great battle, at Sekigahara, and he was named Shogun . The first thing he did was to order all the other daimyo in the country to prove their loyalty by helping with the construction work on his castle. Each of the daimyo was assigned a portion of the construction work, and Ieyasu made it clear that he would see how well each one did to decide how much he could trust them. Since Ieyasu was clearly the strongest man in Japan, everyone tried to do their best to impress him, hoping that they would get rewarded for their hard work.
This "second phase" of construction began in mid-1603. The project was so huge that Ieyasu himself did not see it finished. His grandson, Iemitsu, completed work on the castle almost forty years after it was begun. The first chalenge was just to collect all the materials needed to build the castle. There was no stone suitable for castle-building in the area, so huge stones had to be transported to Edo by ship all the way from Izu province. Three thousand ships were provided by daimyo from western Japan, and this fleet continuously transported loads of stone to Edo for several years until there was enough material to build the walls of the castle. While the stone was being collected at the construction site, teams of workers extended the system of moats surrounding the castle. When Ota Dokan built the first castle in this area, there was only a single moat circling one hilltop. This became the Honmaru ("center circle" or "center ring") of Edo castle. However, Ieyasu and his decendants build a much more elaborate castle, with several rings of of moats and walls to defend against attacks. This layout was typical of most large castles build in the same period. Outside the Honmaru are several other rings of walls and moats that protect the Honmaru. These are called the Ni-no-maru ("second ring"), the Nishi-maru ("west ring") and the Kita-no-maru ("north ring")
The castle buildings themselves were the last to be built. This was a huge project, and thousands of workers were involved in constructing the towers, walls and main buildings of the castle. The main tower was almost 45 meters high, and the base of the tower was 38 meters long and 34 meters wide. The construction work was finally completed in September 1638.
Part of the castle burned down in the Great Meireki Fire, and although most of the buildings were restored, the main tower was never rebuilt. Today, there is just a large lookout mound in the place where the tower used to be. Many reasons are given to explain why the tower was not rebuilt, but it may have been because of a dream that the third Shogun, Iemitsu, had not long after the fire occurred. According to one story, in his dream he saw all the great and powerful leaders of Japan -- Nobunaga, Hideyoshi, and others -- falling to the ground one by one from the top of their castle towers. When he woke up, Iemitsu realized that each of these leaders had lost their power and success not long after they finished building magnificent castles. Since the tower of Edo-jo burned down just a few years after it was completed, Iemitsu decided that this was punishment from heaven for people who tried to act too important, and who built huge castle towers to show how powerful they were. Iemitsu was very superstitious, so he ordered that when Edo Castle was rebuilt, it would not have a tower. Nobody is sure whether this story is true, but even today, Edo-jo is about the only castle in Japan with no castle tower. Instead, it has many low, one- and two-story buildings with huge halls long hallways, elaborate courtyards and beautiful gardens.
I hope you enjoyed your tour of Edo Castle. Very few people get a a chance to see the inside of the Shogun's residence.