Comic John Bishop completed his "week of hell" today after finishing his final marathon to end his punishing Paris to London challenge.
The 45-year-old star cycled, rowed and ran from the French capital to Trafalgar Square, covering more than 290 miles in five days.
Bishop - in severe pain for the final stint after being diagnosed with acute shin splints - finished to the strains of Liverpool anthem You'll Never Walk Alone.
He has battled exhaustion, severe aches and pains, sickness and sleep deprivation since setting off on Monday.
Bishop's trip has raised more than £1.6 million through the BT Sport Relief Challenge.
Bishop has endured a 185-mile cycle, rowed across the English Channel and completed three marathon distances.
The Liverpudlian comedian has been raising cash to pay for vaccinations for African children.
Hundreds of people were waiting at the finish, including fellow comic Jason Manford, waving flags and cheering in central London as he reached his target after hobbling up The Mall with crowds chanting "Bishop, Bishop".
And to compound the suffering, he had to head up the steps in front of the National Gallery to go through the "finish" archway.
A charity spokeswoman said Bishop had been "in a really bad way" towards the end of the final day's running.
The gruelling challenge. which saw Bishop's legs strapped up and regular ice treatments and massages, has raised £1,660,198 so far, organisers said.
After hearing the total, he said: "That's just blown me away. That money's going to change lives. It's going to change the lives of people we don't know."
Bishop, who was already in agony when he set off from Gravesend this morning, said thinking of the effect of his fundraising kept him going.
And he said the support of people along the way had "brought tears to my eyes".
"Just arriving here in Trafalgar Square - amazing," he said.
And playing down his achievement, he told the cheering crowd: "You've changed the lives of people. I haven't."
The final stage of his journey today - at 27 miles, a little over a marathon distance - saw him joined by fellow runners who included his wife Melanie, his brother Eddie and Radio 1 presenter Greg James.
Yesterday Chris Moyles had also kept him company during the run.
He had to take an early rest today when shin splints - sharp pains at the front of the lower leg, often caused by sudden over-exercise - flared up. But he battled on despite severe inflammation.
Earlier in the week, the star completed one day of his challenge after hearing that his son had been involved in a cycle accident. He collided with a bus, smashing through the windscreen, while out of the country.
"There wasn't any permanent damage," Bishop said earlier today, before joking: "The bus was a proper mess."
He was joined by his proud family at the finish.
Bishop's sons Joe 17, Daniel 13 and Luke 15 gathered round their dad to congratulate him on his achievement.
The comedian said of running down The Mall: "I felt like Rocky. It was brilliant."
He said: "I've just been told it's £1.6 million which is just beyond anything I could have dreamt of, to be honest with you.
"And so it doesn't matter what's happened to me. What matters now is that there's £1.6 million available to make people's lives better."
Bishop - who said there were fears he may actually have a stress fracture - admitted he was "in a lot of pain".
He added: "But it's worth it. The pain disappears when you start getting some treatment.
"I've had some fantastic treatment. We've just got to see whether this leg has got acute shin splints or a stress fracture which I'll know about when I get it scanned.
"But it doesn't matter does it, at the end of the day? It can get fixed."
He said he was looking forward to relaxing with his family tonight.
"I'm absolutely shattered," he confessed. "A cup of tea and a lie down will be the answer to everything.
"I'm shattered but I'm also elated. It's great."
He praised the support of the British public, which he said had been "brilliant".
"You can't predict that people are going to beep their horns and wave and give you money on the streets.
"It's so touching and at times it's been emotional because they have no connection to me other than knowing that the money's going to a good cause.
"No other country in the world would you get support for charity like this."
Bishop's journey will be shown in a BBC documentary, to be broadcast in the build-up to Sport Relief Weekend, which takes place from March 23 to 25.