Awadh, also spelled Avadh, also called Oudh, historic region of northern Hindustan, now constituting the northeastern portion of Uttar Pradesh state.

Awadh is situated in the heavily populated heart of the Indo-Gangetic Plain and is known for its rich alluvial soils. It received its name from Ayodhya, the capital of the ancient kingdom of Kosala, which was nearly coextensive with present-day Awadh. It was taken by Muslim invaders in the 12th century and became part of the Mughal Empire in the 16th century. British interest in Awadh began in the 1760s, and after 1800 they exercised increasing control there. It was annexed (as Oudh) by the British in 1856, an action that greatly angered Indians and which has been cited as a cause of the Indian Mutiny (1857–58), the largest Indian rebellion against British rule. Lucknow, the region’s most populous city, was the scene of much fighting during the unsuccessful revolt. In 1877 the British-controlled Oudh region was joined with Agra to form the United Provinces of Agra and Oudh. After India’s independence in 1947 that territory became part of Uttar Pradesh.

Lucknow became important in 1528, when it was captured by Bābur, the first Mughal ruler of India. Under Akbar, his grandson, the city became part of Oudh province. Āṣaf al-Dawlah, who became nawab of Oudh (now Ayodhya) in 1775, transferred his capital from Faizabad to Lucknow. When the Indian Mutiny broke out in 1857, Sir Henry Lawrence, the British commissioner, and the European inhabitants of Lucknow were besieged for several months until rescued by British troops. The British then abandoned the city until the following year, when they regained control over India.

Lucknow is situated at the junction of numerous roads and rail lines, and Chaudhary Charan Singh International Airport is located about 6 miles (10 km) southwest of the central city. The city is a marketplace for agricultural products (mangoes, melons, and various grains are grown locally), and its industries include food processing, manufacturing, handicrafts, and railroad shops. Its population, which has grown dramatically since the late 20th century, surpassed that of Kanpur in the early 21st century to become the most-populous city in Uttar Pradesh.

Lucknow contains notable examples of architecture. The Great Imāmbāṛā (1784) is a single-storied structure where Shīʿite Muslims assemble during the month of Muḥarram. The Rumi Darwaza, or Turkish Gate, was modeled (1784) on the Sublime Porte (Bab-i Hümayun) in Istanbul. The best-preserved monument is the Residency (1800), the scene of the defense by British troops during the Indian Mutiny. A memorial commemorating the Indians who died during the uprising was erected in 1957.