Awadh (known to the British as Oudh) is a region in the northwest of the present Uttar Pradesh. It was a province of the Mughal Empire, and was ruled by a Nawab (a provinicial governer) of this empire. With the weakening of the central institutions of the empire through the 18th century, this province and its Nawab effectively became an independent state, one of the princely states of India.
It signed a treaty with the East India Company in 1765, from which time it effectively became dependent on the company. In the later part of the century Awadh ceded major parts of its territory to the company. The company recruited many of its troops from this kingdom, and maintained a 'resident' there.
In 1856 the East India Company first moved its troops to the border, then annexed the state. Wazir Ali, the then Nawab, was imprisoned, and then exiled by the Company. In the subsequent rebellion of 1857 his 14 year old son Birjis Qadr was crowned ruler. Following the rebel's defeat, he and other rebel leaders obtained asylum in Nepal.
Those company troops who were recruited from the state, along with some of the nobility of the state, were major players in the events of 1857 including the Sepoy Rebellion. It was anticipated that plunder and impoverishment of Awadh would follow the occupation, as had occurred in other regions occupied by the company.
The capital of Awadh was Lucknow through much of its history.