The region was originally called Sapta Sindhu, the Vedic land of the seven rivers flowing into the ocean. The Classical Sanskrit name for the region, as mentioned in the Ramayana and Mahabharata for example, was Panchanada which means "Land of the Five Rivers", and was translated to Persian as Punjab after the Muslim conquests. The later name Punjab is a compound of two Persian words Panj (five) and āb (water) and was introduced to the region by the Turko-Persian conquerors of India and more formally popularised during the Mughal Empire. Punjab literally means "(The Land of) Five Waters" referring to the rivers: Jhelum, Chenab, Ravi, Sutlej, and Beas. All are tributaries of the Indus River, the Chenab being the largest.
Geographically, the province was a triangular tract of country of which the Indus River and its tributary the Sutlej formed the two sides up to their confluence, the base of the triangle in the north being the Lower Himalayan Range between those two rivers. Moreover, the province as constituted under British rule also included a large tract outside these boundaries. Along the northern border, Himalayan ranges divided it from Kashmir and Tibet. On the west it was separated from the North-West Frontier Province by the Indus, until it reached the border of Dera Ghazi Khan District, which was divided from Baluchistan by the Sulaiman Range. To the south lay Sindh and Rajputana, while on the east the rivers Jumna and Tons separated it from the United Provinces.
It encompassed the present day Indian states of Punjab, Haryana, Chandigarh, Delhi, and Himachal Pradesh (but excluding the former princely states which were later combined into the Patiala and East Punjab States Union) and the Pakistani regions of the Punjab, Islamabad Capital Territory and Khyber Pakhtunkhwa.
In 1901 the frontier districts beyond the Indus were separated from Punjab and made into a new province: the North-West Frontier Province.
On 21 February 1849, the East India Company decisively defeated the Sikh Empire at the Battle of Gujrat bringing to an end the Second Anglo-Sikh War. Following the victory, the East India Company annexed the Punjab on 2 April 1849 and incorporated it within British India. The province whilst nominally under the control of the Bengal Presidency was administratively independent. Lord Dalhousie constituted the Board of Administration by inducting into it the most experienced and seasoned British officers. The Board was led by Sir Henry Lawrence, who had previously worked as British Resident at the Lahore Durbar and also consisted of his younger brother John Lawrence and Charles Grenville Mansel. Below the Board, a group of acclaimed officers collectively known as Henry Lawrence's "Young Men" assisted in the administration of the newly acquired province. The Board was abolished by Lord Dalhousie in 1853; Sir Henry was assigned to the Rajputana Agency, and his brother John succeeded as the first Chief Commissioner.