On March 2, 1657, the Great Fire of Meireki destroyed 60 to 70% of the city of Edo (Tokyo) and killed about 100,000 people. The Shogun Tokugawa Ietsuna wished to commemorate the victims of the fire, most of whom were not survived by relatives. For this purpose he erected a monument called the Banninzuka (Mound of a Million Souls) and held a great memorial service conducted by Jun’yo Jōjin (遵誉上人, Holy Priest Junyo) of Zōjō-ji. A temple for prayers to Amida Buddha was built at the same time. This was the origin of the Ekō-in, which today continues to offer a resting place for any soul who did not leave relatives behind, including victims of natural disasters, prisoners, and animals.