West Champaran District was carved out of the old Champaran District in the year 1972 as a result of re-organization of the District in the state. It was formerly a subdivision of Saran District and then Champaran District with its Head quarters as Bettiah. It is said that Bettiah got its name from Baint (Cane) plants commonly found in this district. The name Champaran is a degenerate form of Champaka aranya, a name which dates back to the time when the district was a tract of the forest of Champa (Magnolia) trees & was the abode of solitary asectics.
As per District Gazetteer, it seems probable that Champaran was occupied at an early period by races of Aryan descent and formed part of the country in which the Videha empire ruled. After the fall of Videhan empire the district formed part of the Vrijjain oligarchical republic with its capital at Vaishali of which Lichhavis were the most powerful and prominent. Ajatshatru the emperor of Magadh, by tact and force annexed Lichhavis and occupied its capital, Vaishali. He extended his sovereignty over Paschim Champaran which continued under the Mauryan rule for the next hundred years. After the Mauryas, the Sungas and Kanvas ruled over the Magadh territories. The district thereafter formed part of the Kushan empire and then came under Gupta empire. Along with Tirhut, Champaran was possibly annexed by Harsha during whose reign Huen- Tsang, the famous Chinese pilgrim, visited India. During 750 to 1155 AD , the Palas of Bengal were in the possession of Eastern India and Champaran formed the part of their territory. Towards the close of the 10th century Gangaya Deva of the Kalacheeri dynasty conquered Champaran .He was succeeded by Vikramaditya of the Chalukya dynasty.
During 1213 and 1227,the first Muslim influence was experienced when Ghyasuddin Iwaz the Muslim governor of Bengal extended his influence over Tribhukti or Tirhut .It was however, not a complete conquest and he was only able to have Tirhut from Narsinghdeva, a Simraon king.In about 1320, Ghyasuddin Tughlaq annexed Tirhut to the Tughlaq Empire and placed it under Kameshwar Thakur, who established Sugaon or Thakur dynasty. This dynasty continued to rule the area till Nasrat Shah, son of Allauddin Shah attacked Tirhut in 1530, annexed the territory,and killed the Raja and thus put an end to the Thakur dynasty. Nasrat Shah appointed his son-in-law as viceroy of Tirhut and thence forward the country continued to be ruled by the Muslim rulers. After the fall of Mughal Empire the British rulers came to power in India.
The history of the district during the late medieval period and the British period is linked with the history of Bettiah Raj. Bettiah Raj has been mentioned as a great estate. It traces its descent from one Ujjain Singh and his son, Gaj Singh, who received the title of Raja from the Emperor Shah Jahan(1628-58). The family came into prominence as independent chief in the 18th century during the downfall of the Mughal Empire. At the time when Sarkar Champaran passed under British rule, is was in the possession of Raja Jugal Kishore Singh, who succeeded Raja Dhurup Singh in 1763. The Raj was succeeded by the descendents of Raja Jugal kishore Singh. Harendra Kishore Singh, the last Maharaja of Bettiah, died in 1893, issueless and was succeeded by his first wife, who died in 1896. The estate came under the management of Court of Wards since 1897 and was held by the Maharaja's junior widow, Maharani Janki Kuar.
The British Raj palace occupies a large area in the centre of the town. In 1910 at the request of Maharani, the palace was built after the plan of Graham's palace in Calcutta. The Court Of Wards is at present holding the property of Bettiah Raj.
The rise of nationalism in Bettiah in early 20th century is intimately connected with indigo plantation. Raj Kumar Shukla, an ordinary raiyat and indigo cultivator of Champaran met Gandhijii and explained the plight of the cultivators and the atrocities of the planters on the raiyats. Gandhijii came to Champaran in 1917 and listened to the problems of the cultivators and the started the movement known as Champaran Satyagraha Movement to end the oppression of the British indigo planters. By 1918 the long standing misery of the indigo cultivators came to an end and Champaran became the hub of Indian National Freedom Movement and the launch pad of Gandhi’s Satyagraha.