BBC correspondent in Nairobi
A former Kenyan national has been granted British citizenship ending his 13-month vigil inside Nairobi airport.
Mr Shah had given up his Kenyan passport before going to the UK
Sanjay Shah took part in a British citizenship ceremony - and will receive his passport within a week.
Last year, he was barred from entering the UK and sent back to Kenya. He had already given up his Kenyan passport so he remained at the airport.
He spent 400 days living between the departure lounges on one side and the immigration counters on the other.
Mr Shah washed in the airport lavatories and lived on coffee and food given to him by people working in the airport cafes.
His stay began in May 2004, when immigration officials at Heathrow refused him entry to the UK.
He had flown from Nairobi carrying a British overseas citizen passport - which entitles the bearer to spend a few months in Britain, but no rights to residence.
Sanjay Shah was put on a plane back to Nairobi.
He had already renounced his Kenyan citizenship so - fearing arrest if he ventured outside the airport - he began his lonely stateless existence.
That now ends.
At a brief ceremony at the British High Commission in Nairobi, Sanjay Shah pledged allegiance to Her Majesty the Queen and to the British government.
He then filed his application for a full British passport and was told by officials that he could collect it in less than a week.
Grinning from ear to ear, he said he was delighted now to be a full British citizen and although it had been lonely and uncomfortable at the airport, he did not regret the months he had spent as a stateless being.
He says as soon as his passport comes through he will once again fly to the UK.
His wife and son will join him soon afterwards.
Officials at the High Commission say his protests had been pointless and played no part in the decision to give him a full British passport.