Zardari came only after the promulgation of the controversial National Reconciliation Ordinance (NRO) by then military ruler General Pervez Musharraf.
The NRO granted amnesty to politicians, political workers and bureaucrats who were accused of corruption, embezzlement, money laundering, murder, and terrorism between January 1 1986, and October 12 1999, the time between two states of martial law in Pakistan.
It was declared unconstitutional by Pakistan's Supreme Court on December 16 2009, throwing the country into a political crisis.
While Zardari stepped down, the new Pakistani President would be sworn in tomorrow.
Replacing Zardari would be Hussain, who had emerged as a clear winner in the one-sided contest with ex-judge Wajihuddin Ahmad of Pakistan Tehreek-i-Insaf party.
Born in the historic city of Agra, Hussain, who belongs to an Urdu-speaking ethnic group that migrated from India during partition in 1947, was the PML-N government's candidate.
He comes at a time when the government is framing a new counter-terrorism policy.
Among the many decisions that he will take once he assumes office, the controversial one would be the subject of lifting the moratorium on hanging in Pakistan.
While Prime Minister Nawaz Sharif wanted to lift the moratorium, Zardari wanted it to continue.
