TIMELINE: Events leading up to Pakistan PM Nawaz Sharif's ouster

Pakistani Prime Minister Nawaz Sharif resigned on Friday after the country's top court ruled him unfit for office for failing to disclose income and ordered a criminal investigation into his family over corruption allegations.

The prime minister's fall follows revelations in the so-called "Panama Papers" last year, which revealed Sharif's family had bought posh London apartments through offshore companies.

Here's a timeline:

>> April 4, 2016 - The Panama Papers show involvement of Sharif's family in offshore companies.

>> April 22, 2016 - Sharif asks the Supreme Court to form a commission to investigate the Panama leaks after pressure from the opposition. Cricketer-turned-politician Imran Khan demands an independent probe by the high court itself.

>> April 24, 2016 - Khan threatens protests against Sharif and says the prime minister had lost "moral authority" to rule.

>> May 16, 2016 - Sharif proposes parliamentary commission probe into the scandal; opposition walks out.

>> Oct 28, 2016 - Khan accuses government of placing him under virtual house arrest; supporters fight police ahead of plan to shut down capital in protest.

>> Nov 1, 2016 - Khan backs down from a threat to paralyse capital with a "lockdown" after violence breaks out with many of his supporters injured and the Supreme Court agrees to hear arguments to form a commission to investigate Sharif.

>> Nov 2, 2016 - Supreme Court agrees to set up a judicial commission to probe corruption allegations against Sharif, stemming from Panama Papers leaks.

>> April 20, 2017 - Supreme Court rules there was insufficient evidence to order Sharif's immediate removal but orders a Joint Investigation Team to look further into the source of his family's wealth.

>> July 11, 2017 - Judicial investigators rule Sharif's family accumulated unusual wealth; allies denounce findings.

>> July 27, 2017 - Longstanding political ally and Interior Minister Nisar Ali Khan says he would quit once top court rules on corruption allegations, regardless of the verdict.

>> July 28, 2017 - Sharif resigns after court rules him unfit to hold office and orders more criminal investigations into his family. Court says it disqualified Sharif for not declaring income from a company in United Arab Emirates, which was not in original Panama Papers revelations.