It was bitterly cold on the morning of June 13 1964 when Nelson Mandela arrived on Robben Island. The day before he had been sentenced to life imprisonment at the conclusion of the Rivonia trial, a court case that would shape South Africa's destiny.
His wife Winnie had visited him in jail in Pretoria on the 12th and, hours later, without warning, he and other Rivonia triallists were transported to the island off Cape Town.
As a black man, Mandela was categorised as a "category D" prisoner, the lowest classification. Food rations were allocated according to race. Breakfast for African prisoners was 12 ounces of maize meal with a cup of black coffee. Indian and coloured prisoners received 14 ounces of maize meal, with coffee and bread.
"We were like cattle kept on spare rations so as to be lean for the market. Bodies to be kept alive, not human beings with tastes and a pleasure in eating," fellow prisoner Indres Naidoo wrote of his time on the island.
Category D prisoners were allowed only one visitor every six months and could receive only one personal letter, of no more than 500 words, every six months. Saturday and Sunday were earmarked for visits, and letters were received on a Saturday. Prisoners could give up a visit for two letters.YEARS BEFORE HE COULD SEE HIS DAUGHTERS
Prisoners were not allowed to receive visitors younger than 16, so it was many years before Mandela could see his youngest daughters, Zenani and Zindzi. Zindzi was only 20 months old when she lost her father to the revolution.
Every letter went through the Robben Island censor's office. There could be no mention of prison conditions or other prisoners.
Officials did everything to break Mandela's body, mind and spirit. It was only in 1978 that he was allowed to stop hard labour. Many of his letters went "missing" or were never sent.
Effectively cut off from the world, Mandela had no way of establishing whether his children were safe and being cared for, especially when Winnie was detained for 491 days.
The year 1968 was the beginning of even darker days for Mandela and his loved ones; just as one calamity was dealt with, another would follow.On September 26 his beloved mother, Nosekeni, died and Mandela was denied permission to attend the funeral. Then, on a freezing winter's night, a few hours before dawn on May 12 1969, security police stormed their Soweto home and detained Winnie.
Zindzi and Zenani, then aged nine and 10, clung to her clothes, begging, "Mommy, please don't go." In jail she was tortured and kept in solitary confinement. It was 16 months before she saw her daughters again.
Mandela's letters at the time reveal his pain and anxiety about his wife's ordeal and the fate of his two young daughters. His frustration at being powerless to do anything is always palpable.
News of Winnie's detention reached him on May 17 in the midst of his preparation for his exam finals, then only 25 days away. He was able to write to her only on June 23 1969. In this letter he reminds her of a letter she wrote to him six-and-a-half years previously, one of his most precious possessions, one, he tells her, he takes comfort in rereading countless times.
He quotes some of her words to him: "Most people do not realise that your physical presence would have meant nothing to me if the ideals for which you have dedicated your life have not been realised. I find living in hope the most wonderful thing ... nothing can be as valuable as being part and parcel of the formation of the history of the country."
He reminds her of the power of hope: "It is precisely at the present moment that you should remember that hope is a powerful weapon & one no power on earth can deprive you of."
On the same day he writes a heartbreaking letter to Zenani and Zindzi about their mother's imprisonment: "Perhaps never again will Mummy and Daddy join you in house no. 8115 Orlando West, the one place in the world that is so dear to our hearts."As if that were not enough, tragedy struck again, on July 13, when his eldest son, Thembi, was killed in a car accident. After hearing the news three days later, Mandela sat in his cell, his brown prison blanket wrapped tightly around him, being comforted by his friend, Walter Sisulu. The terse telegram he had received had simply stated: "Please advise Nelson Mandela his Thembekile passed away 13th instant result motor accident in Cape Town."
Later that day he wrote what must have been his most painful letter to Winnie, who was still in prison.
"To lose a mother & a first-born and to have your life partner incarcerated for an indefinite period, all within a period of 10 months, is a burden too heavy for one man to carry even in the best of times. The invisible wound was more painful than the visible one."
Other Mandela letters are poignant windows into his life. He assumes an upbeat tone with his second-born, Makgatho, who is about to turn 20.
On August 31 1970 he writes to Makgatho, saluting him with HEIT MY BLA. He reminds Makgatho that he has not heard from him for a while and is anxious to hear how he is getting on.
He reminisces about Makgatho's boyhood, "when you did not work, grub was galore, clothing plentiful and you slept good".
"Some of your playmates roamed about completely naked and dirty because their parents were too poor to dress them and keep them clean."
The father recalls the son's generosity to his less-fortunate mates by often bringing them home and giving them something to eat. He would also make sure he had enough money to pay the entrance fee to the Trevor Huddleston pool for a needy friend.On December 1 1970 Mandela writes to Sanna Teyise, the owner of the legendary Blue Lagoon restaurant at 10 Von Wielligh Street, Johannesburg. Seretse Khama, Oliver Tambo, Eduardo Mondlane and Joshua Nkomo were some of the political figures who hung out there. Mandela reminds Sanna that regulars urged her to raise her prices, which she bluntly refused to do. Mandela also remembers her landlord taking advantage of the legal dilemma created by her generosity to all races to unreasonably hike the rent.
On March 1 1971 he writes to Zenani, who had just turned 12. He remembers that her birth was a great relief as three months before, Winnie had spent 15 days in prison in conditions that were dangerous for a pregnant woman.
There's the longing of a father for his child. She would only be able to pay him a visit in five years' time, when she was 16. "But I am growing impatient and the coming five years seem longer than eternity."
Mandela fought relentlessly for the rights of his fellow prisoners and himself. His correspondence is detailed and meticulous and he sets out his arguments as a lawyer would, preparing for trial.On May 13 1974 he writes to justice minister Jimmy Kruger, who would later become notorious for his reaction to Steve Biko's death: "It leaves me cold."
Mandela urged Kruger to intervene to enable Winnie's brother to live with her in Orlando West. He sets out several incidents that make Winnie fear for her life. The house had been ransacked, then three men broke in and one of them had tried to strangle her with a cloth. An Alsatian dog she had acquired to guard her was poisoned. Mandela asks Kruger for police protection and for influx control regulations to be relaxed so that Winnie's brother, Msuthu Madikizela, could live with her.
"I am quite certain that if you think my representations are reasonable and substantial, and you consider it your duty to help, all red tape will be brushed aside and our problems could be solved with the stroke of a pen."
In one of Mandela's seminal letters he writes to his friend Joy Motsieloa on February 17 1986. He affirms his belief in his political mission to win change in South Africa.
At this time he would have been writing from his single cell in Pollsmoor Prison. After 1980 he and his fellow political prisoners were allowed access to newspaper and radio news, so he would have been well aware that the country was literally burning and under a state of emergency. Six weeks after this letter, his friend Victoria Mxenge was assassinated."When a man commits himself to the type of life he has lived for 45 years, even though he may well have been aware from the outset of all the attendant hazards, the actual course of events and the precise manner in which they would influence his life could never have been clearly foreseeable in every respect," he writes to Motsieloa.
"If I had been able to foresee all that has since happened, I would certainly have made the same decision, so I believe at least. But that decision would certainly have been far more daunting, and some of the tragedies which subsequently followed would have melted whatever traces of steel were inside me.
"The death of your beloveds and your intimate friends to whom you are linked by countless ties, some going back for several decades, the wide variety of problems to which your family would be exposed in your absence, are personal disasters which are often difficult to endure, and, on most occasions, leaving you wondering whether in this kind of life one should have a family, raise children and make firm friendships."
Mandela suffered every possible pain, every attempt to break his spirit, but despite all the assaults in the course of his journey, his letters reveal the courage, resolution and defiance that greatness is made of.
• The Prison Letters of Nelson Mandela is published by Penguin Random House South Africa, R425..