Oudh (oud) [key], historic region of N central India, now part of the state of Uttar Pradesh. Its early history centers around the ancient kingdom of Kosala, which had Ayodhya (formerly Oudh) as its capital. The region passed under Gupta rule in the 4th cent. A.D. and later it became (11th–12th cent.) the center of the Rajput state of Kanauj. In the 13th cent. it was conquered by the Delhi Sultanate. It became (16th cent.) a province of the Mughal empire, and was subsequently governed by the nawabs of Oudh from their capitals of Faizabad (1724–75) and Lucknow (1775–1856). The annexation (1856) of Oudh as a British province was a contributing cause of the Indian Mutiny (1857–58). In 1877, Oudh was joined with the presidency of Agra to form the United Provinces, which subsequently became the Indian state of Uttar Pradesh.