But it could have unravelled in less than an hour as the man at the centre of the overthrow sat in a plane circling above Karachi, battling to land before the plane ran out of fuel.

But Prime Minister Nawaz Sharif's failure to stop General Pervez Musharraf from uniting the army showed how well prepared the military had been to defend their high command and take on the civilian government.

Conspiracy in Islamabad

Events began on Tuesday when General Musharraf, on an official visit to Sri Lanka, received intelligence that tension between the prime minister and himself had finally reached a head. Mr Sharif and intelligence chief General Ziauddin, secretly meeting in Islamabad, were to move against him that very day.

The sacking would be presented as a "retirement" and General Ziauddin would step into the most powerful job in the Pakistani military.

Acting immediately, General Musharraf dashed for the Karachi-bound Pakistan International Airlines PK805 flight from Colombo, leaving at 1545 local time.

Back in Islamabad, chief of the general staff Lieutenant-General Mohammed Aziz, and head of the 10th Corps Lieutenant-General Mahmood Ahmed, began plans to mobilise troops stationed in nearby Rawalpindi.

Sharif makes his move.

Nawaz Sharif formally appointed General Ziauddin at his official residence at 1540 that afternoon.

But it is believed that it was at this stage they realised that events may not be going to plan.

The English-language The News newspaper reports that within 30 minutes General Ziauddin had failed to find a single senior officer prepared to accept his command.

Suspecting that General Aziz and Ahmed had already set events in train, Mr Sharif and General Ziauddin realised that they had to prevent General Musharraf from returning. They had less than 200 minutes to stop the plane landing.

General Ziauddin reportedly told the prime minister that he could take control of the army if the flight was prevented from reaching Karachi.

Mr Sharif agreed to the high-stakes plan and at about 1600, his staff officially announced General Musharraf's retirement.

It was all the excuse the army high command needed and an hour later troops from 111 Brigade of the 10th Corps were on their way to Islamabad.

Counter attack

The next 90 minutes changed the future of Pakistan. As troops poured onto the streets of the capital, the 111 Brigade stormed the state television station in Islamabad, watched by international correspondents who had gathered outside.

Inside, officers were heard shouting "take it off! take it off!" and minutes later Pakistani families saw the television picture cut as the signal was shut down.

Elsewhere, troops disarmed security guards protecting Mr Sharif's residence. With the odds already heavily in their favour, the generals entered the home.

In an interview with the BBC, Mr Sharif's son Hasan, a student in London, told what his relatives had recounted to him.

"My father was about to leave to address the nation," he said. "At that moment he was placed under house arrest.

"The generals and commanders asked for his resignation and that he should take back all the orders to sack the army chief of staff.

"Obviously, he rejected both the idea of resignation and taking back his orders."

Faced with the prime minister's refusal to accept the coup, the officers reportedly escorted him from the building and placed him in a guest house near to the airport.

One report also suggests that troops in the Sharif home town of Lahore prevented other members of his family fleeing to Kuwait.

Soldiers fanned out across the nation, taking control of administrative buildings in every province and placing Sharif loyalists and the cabinet under house arrest.

But one man was still needed to complete the coup, and he was still in the air.

Stand-off over Karachi.

General Musharraf approached Karachi airport at about 1830.

But as the army were busy cutting telephone lines, air traffic control refused the plane, holding some 200 passengers, permission to land.

According to the charges now laid against Nawaz Sharif, air traffic controllers ordered the flight to Nawabshah in the Sindh province where, it is believed, the prime minister had despatched his own jet and security team to take the general into custody.

Smelling a rat, Musharraf apparently ordered the pilot to ignore the order and continue to circle Karachi, despite the fact that fuel was now running low.

The general is said to have personally spoken with air traffic controllers, demanding the right to land, saying that they did not have enough fuel to go elsewhere.

The controllers initially refused but as soldiers surrounded the control tower they thought again and General Musharraf finally reached home soil more than hour late at 1947. Gen Musharraf has since said that the plane had only seven minutes of fuel remaining.

After the general whisked though the airport, officers across the nation reported in a hastily prepared operational command conference that the coup was virtually complete.

They controled the TV stations, administrative buildings, the power and communications infrastructure - and had the entire cabinet under guard.

Musharraf addresses the nation

At 2215 the army restored television broadcasts.

Fifteen minutes later, a terse announcement ran across the bottom of the screen stating that Prime Minister Nawaz Sharif had been dismissed.

The continuity announcer later added that General Pervez Musharraf, who had spent a tense 200 minutes in the air, would address the nation.

As his prerecorded statement was broadcast for the first time at 0250 Wednesday morning, the Sharif era appeared to come to a close.