The Shaka era (IAST: Śaka, Śāka) is a historical Hindu calendar era (year numbering), the epoch (its year zero) of which corresponds to Julian year 78. The era has been widely used in different regions of India as well as in SE Asia. History There are two Shaka era systems in scholarly use, one is called Old Shaka Era, whose epoch is uncertain, probably sometime in the 1st millennium BCE because ancient Buddhist and Jaina inscriptions and texts use it, but this is a subject of dispute among scholars. The other is called Saka Era of 78 CE, or simply Saka Era, a system that is common in epigraphic evidence from southern India. A parallel northern India system is the Vikrama Era, which is used by the Vikrami calendar linked to Vikramaditya. The beginning of the Shaka era is now widely equated to the ascension of king Chashtana in 78 CE. His inscriptions, dated to the years 11 and 52, have been found at Andhau in Kutch region. These years are interpreted as Shaka years 11 (89 CE) and 52 (130 CE). A previously more common view was that the beginning of the Shaka era corresponds to the ascension of Kanishka I in 78 CE. However, the latest research by Henry Falk indicated that Kanishka ascended the throne in 127 CE. Other historical candidates have included rulers such as Vima Kadphises, Vonones, and Nahapana. According to historian Dineshchandra Sircar, the historically inaccurate notion of "Shalivahana era" appears to be based on the victory of the Satavahana ruler Gautamiputra Satakarni over some Shaka (Western Kshatrapa) kings. An account claims that the emperor Shalivahana, grandson of legendary emperor Vikramaditya defeated the Shakas in 78 CE, and the Shaka era marks the day of this conquest. This legend has been mentioned in the writings of Brahmagupta (7th century CE), Al-Biruni (973–1048 CE), and others. Over time, the word "Shaka" became generic, and came to be mean "an era"; the era thus came to be known as "Shalivahana Shaka". Usage The earliest known users of the era are the Western Satraps, the Shaka (Indo-Scythian) rulers of Ujjain. From the reign of Rudrasimha I (178–197), they recorded the date of minting of their coins in the Shaka era, usually written on the obverse behind the king's head in Brahmi numerals. The use of the calendar era survived into the Gupta period and became part of