The district of Kullu came into being on November 1, 1966. Various historical evidences including inscriptions on coins etc., accounts of travelers and other printed references point out to the antiquity of the tract and the people which constitute the district Kullu of the present. The history of Kullu has been traced some 2000 years back in time. The word ‘Kullu’ is speculated to have been derived from the word ‘Kuluta’ which was found inscribed on a coin from the first century A.D. The first king (Raja) mentioned in historical record is Virayasa whose name figures on that coin as ‘Virayasa, King of Kuluta’. The Chinese pilgrim, Hiuen Tsang, is believed to have described the modern Kullu as Kiu-lu-to situated at 117 miles to the north-east of Jalandhar. The tract has also been referred to as ‘Kulantapitha’, which translates to ‘the territory which marks the end of Kula i.e. the socio-religious system of the mainland’ or ‘the end of the habitable world’.
The tract is said to have been first ruled by the Pal kings, who were succeeded by the Singh kings, believed to be descendants of the Pal kings. According to known history, the kingdom of Kullu was founded in the first century A.D. by Behangamani Pal, who is speculated to have come from Prayag near Allahabad. It appears that the people of the higher valley of Kullu were suffering under the repressive regime of the Thakurs of Spiti then and a keen desire to overthrow the Thakurs was smoldering in their hearts. Behangamani Pal overthrew the Thakurs and established the first ruling dynasty of Kullu. The rule of the Pal kings continued till about A.D. 1450 and Raja Kelas Pal was the last in that line. After him there was long break of about 50 years and it appears that the Thakurs and the Ranas might have captured power during this period.
After this interregnum, Sidh Singh, who became the Raja of Kullu in A.D. 1500, is recognized as the first of the line of the Singh kings. The local folklore narrates the story of Goddess Hidimba granting the kingdom of Kullu to Sidh Singh. Hidimba is respected as the grandmother and the patron-deity by the royal family of Kullu till date. The next important king of Kullu was Raja Jagat Singh (A.D.1637-1672) who incorporated Lag into the kingdom of Kullu. The original capital of the state of Kullu was at Jagatsukh where the early kings ruled for twelve generations. Raja Visudh Pal transferred the capital to Nagar and later Raja Jagat Singh transferred it to Sultanpur. The famous idol of Raghunath was brought from Ayodhya to Kullu during the reign of Raja Jagat Singh to remove a curse which a Brahmin had casted upon Jagat Singh. Jagat Singh put the idol on the throne, proclaimed himself to be merely the first servant of the temple, and the curse was removed. Since then, the Rajas of Kullu ruled the state in the name of Raghunath, who became the principal deity of the Kullu valley. With this incident Vaishnavism established itself in a land where Shaivism and Shaktism were the dominant denominations. During the period of the Mughal rule, Kullu was subject to the suzerainty of the Mughal emperors and used to pay tribute to them.
In A.D. 1672, river Sutlej became the state boundary in the south and Outer Saraj (consisting of Ani and Nirmand of the present times) became a part of Kullu. In territorial terms, Kullu reached its zenith under Raja Man Singh extending from Upper Lahaul in the north to Shimla in the south. Around A.D. 1800, the authority of the Mughal empire declined and Kullu started paying tribute to the Gorkhas and to Sansar Chand, the Katoch Raja of Kangra. In A.D. 1839, the Sikhs captured Kullu state from Raja Ajit Singh and in A.D. 1846 they ceded it to the British Government. Consequently, Kullu, along with Lahaul & Spiti, became a part of the district of Kangra, as a sub-division under the control of an Assistant Commissioner. The British gave sovereign powers to Thakar Singh within the jagir of Rupi and in A.D. 1852 his son Gyan Singh was given the title of Rai instead of Raja.
Until 1960, the tract of Lahaul & Spiti was part of the Kullu tehsil. Kullu was declared to be a district of Punjab in 1963 and on November 01, 1966 it became a district of Himachal Pradesh. In the British times, all the modern government buildings, hospital and government bungalows were built around the Dhalpur grounds (proximate to Sultanpur, the old capital). Dhalpur continues to be the nerve centre of the district administration till date.