Sibsagar, a town and district of British India, in eastern Bengal and Assam. The town is situated on the Dikhu river, about 9 m. from the left bank of the Brahmaputra, being picturesquely built round a magnificent tank, covering an area of 114 acres. Pop. (1901) 5712. In 1907 the transfer of the district headquarters to Jorhak (pop. 2899), on the Disai river, was sanctioned.
The District Of Sibsagar has an area of 4996 sq. M. It consists of a level plain, much overgrown with grass and jungle, and intersected by numerous tributaries of the Brahmaputra. It is divided by the little river Disai into two tracts, which differ in soil and general appearance. The surface of the eastern portion is very flat, the general level being broken only by the long lines of embankments raised by the Ahom kings to serve both as roadways and as a protection against floods. The soil consists of a heavy loam of a whitish colour, which is well adapted for rice cultivation. West of the Disai, though the surface soil is of the same character, the general aspect is diversified by the protrusion of the subsoil, which consists of a stiff clay abounding in i:on nodules, and is furrowed by frequent ravines and water-courses, which divide the cultivable fields into innumerable small sunken patches or holas. The chief river is the Brahmaputra, which is navigable throughout the year by steamers. The tributaries of the Brahmaputra comprise the Dhaneswari, the Dihing, the Disang and the Dikhu, all flowing in a northerly direction from the Naga Hills. Included within the district is the island of Maguli, formed by the silt brought down by the Subansiri river from the Himalayas and deposited in the wide channel of the Brahmaputra. Coal, iron, petroleum and salt are found. The climate, like that of the rest of the Assam valley, is comparatively mild and temperate, and the annual rainfall averages about 94 in.
In 1901 the population was 597,969, showing an increase of 24% in the decade. Sibsagar is the chief centre of tea cultivation in the Brahmaputra valley, which was introduced by the Assam Company in 1852. It contains a large number of well-managed tea-gardens, which bring both men and money into the province. There are also several timber mills. The Assam-Bengal railway serves the southern part of the district, and a light railway connects this line with Kalikamukh on the Brahmaputra, itself an important highway of communication.
On the decline of the Ahom dynasty Sibsagar, with the rest of the Assam valley, fell into the hands of the Burmese. As a result of the first 'Burmese war (1824-1826) the valley was annexed to British India, and the country now forming Sibsagar district, together with the southern portion of Lakhimpur, was placed under the rule of Raja Purandhar Singh, on his agreeing to pay a tribute of 5000. Owing to the raja's misrule, Sibsagar was reduced to a state of great poverty, and, as he was unable to pay the tribute, the territories were resumed by the government of India, and in 1838 were placed under the direct management of a British officer.
See Sibsagar District Gazetteer (Allahabad, 1906).