The accession of Asaf-Ud-Daula, the fourth Nawab, brought a great change in Awadh politics. He moved the court of Awadh from Faizabad to Lucknow in 1775. When the court moved to Lucknow, the kernel of the court, as if, shed its old husk and acquired a new one and the city largely grew in and around the existing town to accommodate the influx of the people. There emerged a powerful Shia culture, in constant interaction with Shia heart lands of Iran and Iraq. The increasing number of Shia emigrants from Iranian cities veritably transformed Lucknow into a great intellectual center.
The Nawab constructed Daulat Khana, the large palace – garden complex as residence for himself, the major mosques like Asfi Masjid, enlarged the Chowk and set up dozen major markets to form the core of royal quarter of the city. He built the gateway, Rumi Darwaza and Bara Imambara to provide succor to the victims of famine of 1784. The arched roof of Imambara, built without a single beam or pillar for support, is one of the largest of its kind in the World. The Bhul Bhulaiya at Imambara is a unique labyrinth of intricate balconies and passages, with 489 identical doorways, which make one feel being lost. Asaf- Ud-Daula also built Bibiyapur Kothi and Chinhut Kothi. Overwhelmed by the design of Constantia built by Claude Martin he purchased it, offering to give ten lakhs of gold coins. However, before the transaction could be completed, the Nawab died in 1798 and was laid to rest in the magnificent Imambara built by him. The British absorbed Allahabad and the adjoining region in the same year.