Below is a timeline of how Pakistan lost it's premier:

Mid 2009: The Supreme Court of Pakistan suspended the National Reconciliation Ordinance (NRO) which was constituted by the ex-president Pervez Musharraf, granting immunity to politicians and businessmen who had various corruption charges among other legal charges pressed against them.

Late 2009: All cases suppressed under the NRO were brought back and reopened. Supreme Court ordered the government to seek possibilities of bringing back national money hidden in foreign bank accounts by Pakistani politicians and businessmen.

2010-2011: SC pushed the government to take effective measures in making sure that corruption cases against President Zardari are reopened in the court of law. PM Gilani was asked to write a letter to the Swiss authorities that directing them to re-open the cases against Zardari, who was given amnesty by ex-president Pervez Musharraf under the National Reconciliation Ordinance (NRO).

2011: The Gilani administration kept stalling the court's ruling on re-opening graft cases against President Asif Ali Zardari. Supreme Court warned the government of action if it fails to take the necessary actions. The governement was given a a deadline of 10 January 2012.

Jan 16, 2012: PM Gilani, yet failing to comply with court's orders refused to write the letter and was subsequently issued a legal notice charging him with contempt of court.

Jan 19, 2012: PM Gilani appeared before the court and stood his stance that the President had international immunity and that he could not go against the constitution and write the letter.

April 26, 2012: The Supreme Court convicted Prime Minister Gilani for contempt of court and sentenced him to a symbolic '30 second' imprisonment inside the courtroom. Gilani appealed against the court verdict and resumed office despite political pressure from the opposition Pakistan Muslim League(Nawaz) and Imran Khan's Pakistan Tehreek-e-Insaaf.

May 28, 2012: The verdict was forwarded to the speaker of National Assembly who ruled in favour of Gilani enabling him to continue as Pakistan's Prime Minister. With Election Commission absent a reason to disqualify Gilani, he decided to withdraw his appeal against the court verdict and refused to leave office.

Jun 19, 2012: The Supreme Court of Pakistan disqualified Yousuf Raza Gilani from the premiership. The court pronounced Gilani as ineligible since 26 April, the date of Supreme Court's verdict and PM Gilani's conviction. Stating that all order's given from his office during this time period shall be nullified.