Ambala was one of the Cis-Sutlej states, the small Sikh chiefships between the Sutlej and the Jamuna that came under British protection in 1809 rather than into Ranjit Singh Ji's state. When the ruling family failed to produce an heir the territory lapsed to the Company, and a cantonment was laid out in 1843.
In 1857 the greased cartridge trouble surfaced at Ambala before it surfaced at Meerut. Musketry instruction for the whole of the Bengal Army's northern regiments ran through the depot here, and reports of refusals reached the authorities in March and April. The rising broke out at Meerut on 10 May. The delay at Ambala, and what the command did or failed to do with the warning, is argued over in the literature on 1857.
The town has two distinct halves, the city and the cantonment, several kilometres apart with open ground between them. Ambala Cantt has its own railway station and the two halves have kept separate characters for a hundred and eighty years.
Ambala went to Haryana in 1966. It had been the divisional headquarters for a large part of eastern Punjab and the Punjab and Haryana High Court sat there before Chandigarh. The cloth market and the scientific instrument trade are the town's own, not inherited from the cantonment.
The cantonment was established in the 1840s and became one of the largest in northern India, on the watershed between the Indus and the Ganga systems.
The rising of 1857 began at Ambala days before Meerut, in the form of unrest that the officers suppressed locally, which is a detail the standard accounts of that year usually leave out.
It went to Haryana in 1966 and its Punjabi speaking population stayed. The town is a rail junction, a cantonment and a market and it has never been written about as anything else.