Chaharshanbe Suri
The festival has its origin in ancient Iranian rituals. The ancient Iranians celebrated the festival of Hamaspathmaedaya (), the last five days of the year in honor of the spirits of the dead. This is today referred to as Farvardinegan. They believed that the spirits of the dead would come for reunion. The seven holy immortals () were honored, and were bidden a formal ritual farewell at the dawn of the New Year. The festival also coincided with festivals celebrating the creation of fire and humans. By the time of the Sasanian Empire, the festival was divided into two distinct pentads. They are known as the lesser and the greater . The belief had gradually developed that the "lesser " belonged to the souls of children and those who died without sin, while the "greater " was for all souls.