The 28-year-old marathon runner, who entered the Games as a stateless athlete, competed under the Olympic flag and wore the black and grey uniform of an Independent Olympic athlete.
Marial, from war-torn South Sudan, was one of just four independent athletes chosen by the International Olympic Committee to compete at the Games. Three competitors from the former Netherlands Antilles also appeared under the Olympic flag.
Ten years previously, Marial fled a refugee camp during the civil conflict that has raged for 20 years and displaced four million of his African countrymen – and claimed the lives of a staggering 28 of his family members.
A budding athlete from the age of eight, he arrived in America via Egypt – having left his family behind – but failed to attain US citizenship, despite attending Iowa State University. Offered a place in Sudan’s national squad, he turned it down, as he felt that representing the country would betray their memory.
However, Marial said he believed competing at the London Games would honour them – and the IOC stepped in to represent him, as South Sudan, a new country, has yet to be recognised as a state.
He told a press conference before the Games: ‘Growing up in the war it was dangerous and hard. It was about survival of the fittest. If you survived one day, okay – but what’s going to happen the next day?
‘Growing up there, I did not know the outside world. When I left the village and [went] to the city and came to Cairo and the United States, the world kept opening and opening. There are other things, not just about killing each other.
‘I feel fortunate to have that, to have that background. That’s helped me with my running and my everyday life.’
Marial had not seen his family for 20 years when he arrived in London. But he said they had walked 60km to get to Pangrieng, the nearest town with a TV to watch him compete.
In the event, he finished 47th out of a field of more than 100 with a time of 2:19:32 – an astonishing achievement considering his peripatetic life over the last decade has not given him the best training for Olympic competition.
He told journalists: ‘South Sudan has finally got a spot in the world community. Even though I will not carry their flag in this Olympic Games, the country itself is there. The dream has come true. The hope of South Sudan is alive.’
Now, Marial hopes his story will inspire members of the next generation in South Sudan. After arriving at the Olympic Village, he added: ‘I want to thank the International Olympic Committee for giving me the opportunity to be here and raise awareness about refugees and all the people around the world who don’t have a country. To run under the Olympic flag – I feel like I’m representing the whole world.’