Tirgan is an ancient Iranian tradition which is still celebrated in various regions of Iran, including Mazenderan, Khorasan, and Arak. It is widely attested by historians such as Gardezi, Biruni, and Masudi, as well as European travelers during the Safavid era. The celebration is dedicated to Tishtrya, an archangel who appeared in the sky to generate thunder and lightning for much needed rain. Legend says that Arash the Archer was a man chosen to settle a land dispute between the leaders of the lands Iran and Turan.