Although the former South African president has been sent home from hospital, he is still in a critical and unstable condition

The world's most crowded and speculated-upon bedside vigil took a fresh turn on Sunday when Nelson Mandela was sent home from hospital, though still in a critical and sometimes unstable condition.

South Africa's first black president had lain in the Mediclinic heart hospital in Pretoria for 12 weeks. With his great life hanging by a thread, rumours circulated, news teams scrambled from around the world and South Africans braced themselves for the worst, with crowds laying flowers outside the hospital and some saying it was time to "let him go".

Yet a sunny but cool Sunday morning – the first day of spring in South Africa – brought a scene that had seemed unthinkable, with Mandela deemed well enough to make the 31-mile journey home to Johannesburg. TV crews, photographers and curious neighbours in the tree-lined suburb of Houghton watched an ambulance marked "paramedical intensive care" trundle into a house that, officials said, has been "reconfigured" to allow him to continue receiving intensive care.

As with every previous twist in the saga of the 95-year-old's fragile health, the official announcement was scrutinised for hidden clues and there was speculation about whether it might offer false hope.

But the anti-apartheid hero's grandchildren were upbeat. Ndileka Mandela described herself as "happy as hell", while Mbuso Mandela, who visited his grandfather on Sunday morning, said: "He's OK, he's OK – he's old, you know. I'm very positive. Positivity begets positivity. I always knew he was coming home and as a family we rejoice. We thank the country for their support and well wishes."

Mac Maharaj, a friend of Mandela and spokesman for President Jacob Zuma, also suggested that the statesman was in recovery mode, stating: "We would like to wish him all the best as he continues his recovery at his Johannesburg home."

Using Mandela's clan name, he continued: "Madiba's condition remains critical and is at times unstable. Nevertheless, his team of doctors are convinced that he will receive the same level of intensive care at his Houghton home that he received in Pretoria. His home has been reconfigured to allow him to receive intensive care there. The healthcare personnel providing care at his home are the very same who provided care to him in hospital. If there are health conditions that warrant another admission to hospital in future, this will be done."

Mandela was taken to hospital with a recurring lung infection on 8 June when, it later emerged, his military ambulance suffered a breakdown and had to wait on the roadside for backup. When Zuma announced that Mandela's condition deteriorated, then cancelled a foreign trip, it seemed the end was near. Speculation about a life support machine that might or might not be switched off reached a critical mass.

But journalists flying in from around the world found themselves camped outside the hospital day after day with diminishing returns. Mandela's daughter Makaziwe branded them "vultures".

The Nobel peace laureate clung on and, against the odds, was joined by his family for a celebration of his 95th birthday on 18 July, a day marked around the world. Some family accounts even described him sitting up in bed with earphones watching TV.

Maharaj added: "During his stay in hospital from the 8t June 2013, the condition of our former president vacillated between serious to critical and at times unstable. He has received full medical support and continues to do so. He has also received visits from family, friends and colleagues. Despite the difficulties imposed by his various illnesses, he, as always, displays immense grace and fortitude."

The nerve-wracking months also witnessed an internal Mandela family dispute that many regarded as lacking the same "grace". Sixteen relatives won a court case against his eldest grandson, Mandla, ensuring that the bones of Mandela's three late children were dug up and moved to the village of Qunu – crucial to the final resting place of Mandela himself.

An alleged leak from the court documents suggested the matter was urgent because Mandela was in a "permanent vegetative state", being kept alive by a breathing machine and facing "impending death". The claim was vehemently denied by Mandla, visitors to the hospital and the government.

On Sunday Mandla welcomed his grandfather's discharge but then could not resist a swipe at his adversaries in the family. "It is a day of celebration for us that he is finally back home with us," he began. "We are deeply touched and thankful for the outpouring of prayers and the overwhelming messages of goodwill from people the world over. Finally everyone can breathe a sigh of relief that our prayers have found favour with the almighty."[His] discharge is particularly heartening because it flies in the face of those who have been busy spreading lies that he was in a 'vegetative state' and just waiting for his support machines to be switched off, in effect declaring him dead while he was fully alive and showing his fighting spirit that has defined him over the many years of his life."

Mandela has been particularly vulnerable to respiratory problems since contracting tuberculosis during his 27-year imprisonment under white minority rule. The bulk of that period was spent on Robben Island, where he and other apartheid-era prisoners spent part of the time toiling in a limestone quarry.

Mandela made his last public appearance waving to fans from the back of a golf cart before the football World Cup final in Johannesburg in 2010. In April the national public broadcaster Denis Goldberg, an anti-apartheid activist who stood trial with Mandela half a century ago, welcomed his return home. "I'm very happy for him to be able to have more company and not be isolated. His family will now be able to drop in."

Goldberg, who visited Mandela in hospital on 1 July, added: "What a fighter, but he's not out of the woods yet. He still has crises from time to time but he recovers and gets on with it." © Guardian News and Media 2013

["South African former President Nelson Mandela waves as he arrives at a polling station in Johannesburg on April 22, 2009" via AFP]