Prime Minister Narendra Modi, Chief Minister Akhilesh Yadav, Rahul Gandhi, Mayawati and other leaders campaigned exhaustively here, addressing multiple rallies.
Uttar Pradesh, the country's biggest state with over 22 crore people, has been through long spells of President's rule, hung verdicts, mass defections and mid-term polls.
Bahujan Samaj Party leader Mayawati ended a spell of instability when in 2007, she won a spectacular victory based on her social engineering formula that went beyond her traditional Dalit vote bank to reach out to the upper castes. In the next election in 2012, it was Akhilesh Yadav's turn to celebrate after winning comfortably.
Uttar Pradesh has been placed under President's rule 10 times, the last time in 2002.
There is hardly any combination that has not been tried in the state.
In the late 1990s, the BJP and Mayawati came together with a plan to rotate the chief minister's post between the parties for a six-month period - an experiment that didn't work.
Mid-term elections have been called as many as seven times; the last time was in 1998.
Uttar Pradesh was the base and the favourite hunting ground for the Congress in the initial years after Independence, when many top leaders leading state and national politics. But it was this state that became the first to get a non-Congress government.
In 1967, Charan Singh and his socialist colleagues left the Congress to form the Bharatiya Kranti Dal and formed the government.
(With inputs from PTI)