After Ieyasu Tokugawa started to rule the Kanto (east Japan) region, he accorded cordial protection to Zojoji as the family temple of the Tokugawa family. Parallel to the expansion of the Edo Castle, a large-scale construction project was also commenced for Zojoji. After that, Zojoji came to be widely known as one of Japan's principal Buddhist temples. Located in its precincts are the tombs of six Tokugawa Shoguns, Imperial Princess Kazunomiya (wife of Shogun Iemochi), and wives and children of shoguns. Nowadays, these tombs serve as a reminder of the prosperous Edo Period.
The graves of Hidetada and the monument to his wife Suugen'in, Ienobu, and Ietsugu had been designated National Treasures of Japan, but were burned in World War II. At present, parts of two of their graves have the distinction of being Important Cultural Properties. Additional graves are located in the cemetery behind the Great Hall.
Enshrined in this building is the Black Image of Amida Buddha, which was deeply worshiped by Ieyasu Tokugawa. This wonder-working image is said to have repeatedly saved Ieyasu from dangers and enabled him to win battles. Since the Edo Period, it has been widely revered as a Buddhist image which brings victory and wards off evils.