Both Sharif's terms as prime minister resulted in corruption allegations [AFP]

During his second term of office - from 1997 to 1999 - he was overthrown in a bloodless coup by Pervez Musharraf, whom he had appointed chief of Pakistan's military.

Allegations of corruption dogged his premierships, but he later rebuilt his political credibility on the back of his opposition to Pervez Musharraf, Pakistan's former president.

The scion of a wealthy family dynasty with interests in steel, sugar and paper, Sharif was handpicked in 1981 by Zia ul-Haq, Pakistan's then-military ruler, to become one of the youngest-ever finance ministers for the Punjab province.

He served as chief minister of Punjab from 1988 to 1990, when he challenged the premiership of Benazir Bhutto, who became prime minister after Zia's death in a plane explosion.

Sharif - with the military's blessing - was elected prime minister in 1990, after Bhutto's dismissal.

But after three years he was sacked on corruption charges following differences with Ghulam Ishaq Khan, the then-president.

Instead of accepting the dismissal, Sharif launched a scathing attack on Khan, who was widely considered his former mentor and a top representative of the military-led establishment.

Second term

Sharif bounced back to the premiership in 1996 after the dismissal of Bhutto's second government on grounds of corruption.

He then won a massive two-thirds majority in 1997 elections, which emboldened him to take on the army - the institution which has ruled Pakistan for more than half its existence since independence 60 years ago.

Sharif also expanded the powers of his office, reversing a constitutional amendment that allowed the president to dismiss the prime minister.

Later, Pakistan's western allies grew concerned when he sought to introduce Islamic law, with himself as the so-called "commander of the faithful".

Overthrown

In 1998, Sharif appointed Musharraf as chief of the army, but relations between the two soured over a skirmish with Pakistan's neighbour India in the disputed Himalayan region of Kashmir.

Suspecting that Musharraf was planning to overthrow him, he tried to sack him while the army leader was en route from Sri Lanka.

But the army moved quickly, bringing Musharraf back to Pakistan and installing him as chief executive.

Musharraf had Sharif and his brother Shahbaz tried on charges of hijacking, terrorism and attempted murder and, while Shahbaz and six co-defendants were acquitted in April 2000, Sharif was convicted and sentenced to life imprisonment.

But the military government later agreed to commute his sentence to exile in Saudi Arabia, and he quietly left Pakistan with 19 members of his extended family in December 2000.

Return to Pakistan

A Pakistani court ruled in August 2007 that the former prime minister had an "inalienable right" to return to Pakistan, and he flew home briefly on September 10.

However, on arriving in Islamabad, he was charged with corruption and sent back into exile in Saudi Arabia.

Sharif joined forces with the PPP to form part of the ruling coalition [AFP]

He was not deported and the move ended his seven years in exile.

But Sharif was banned from participating in the polls, with the Electoral Commission saying it was upholding objections from other candidates that Sharif was ineligible to run because he was convicted of criminal charges in the wake of Musharraf's coup.

Sharif said the convictions were politically motivated.

After the elections, Sharif joined forces with the victorious Pakistan People's Party (PPP) to form part of the ruling coaltion and oppose Musharraf.

But after the former army leader stepped down from office, the coaltion fell apart over a row about the reinstatement of judges Musharraf had sacked.

In May 2008, Sharif's PML-N announced it was leaving the coalition after blaming the PPP for failing to finalise a decision on reinstating the judges.

Its ministers, including Sharif, resigned.

In February 2009, a Supreme Court ruling banned Sharif and his brother from holding office over the charges of hijacking and terrorism charges levelled against them during the Musharraf era. 

The decision caused nationwide mass protests and the government allowed Sharif to appeal the decision.

On July 17, 2009, Pakistan's supreme court acquitted Sharif of all charges of hijacking, effectively removing all barriers to him running for office in parliamentary elections scheduled for 2013.