He is someone I was proud to raise my voice for, in support of his release.

Nelson was born Rolihlahla Mandela in 1918, and his father had four wives, and fathered a total of 13 children. It's a tribute to his fine intellect that he became the first member of his family to attend a school at the age of seven, where his teacher found his name too hard to pronounce, and renamed him 'Nelson', after the British admiral, Horatio Nelson.

It was when he was studying for a degree at Fort Harte University, that Mandela got involved in his first political protest. He became involved in a boycott by the Students' Council against university policies, which resulted in him being asked to leave the college.

He moved to Johannesburg, where he became prominent in the African National Congress's (ANC) 1952 Defiance Campaign, and the 1955 Congress of the People, whose adoption of the Freedom Charter provided the basis of the anti-apartheid cause.

Nelson and fellow lawyer and friend, Oliver Tambo, provided free or low-cost legal counsel to many blacks, who would otherwise have been left without legal representation.

What I admired about Mandela is that he tried his best to be committed to nonviolent mass struggle. His move to armed struggle was a last resort, when increasing repression and violence from the state convinced him that the years of non-violent protest against apartheid had achieved nothing.

He became leader of the ANC's armed wing, Umkhonto we Sizwe, and coordinated a campaign against government and military targets, and was arrested in 1962, having been on the run for 17 months.

He and other prominent ANC leaders were almost all found guilty, and sentenced to life imprisonment at the Pretoria Supreme Court. Nelson was sent to Robben Island, where he spent the next 18 of his 25 years imprisonment. He had a very hard time there, because he was black, and he was also a political prisoner. Even through this hard time, Mandela studied law by correspondence at the University of London. He was then moved to Pollsmoor Prison for the last seven years. President Botha offered Mandela release in 1985, on condition that he renounced armed struggle, which he refused to do.

My former husband and musical partner, John Faulkner, wrote a song called 'Lion in a Cage' about Mandela. "Locked in a jail for 25 years/ Held like a lion in a cage of tears."

I immediately recognised it for a powerful and finely-crafted piece of writing, and one whose sentiments I wholeheartedly endorsed. I agreed at once to record it for a new album I was working on. It became the title track and was released as a single.

Meanwhile, local and international pressure began to mount on the South African government to release Mandela, and when Botha was replaced by President F W de Klerk, he announced Mandela's release in February 1990.

It transpired that his release from jail came shortly after the song, 'Lion in a Cage', came out, and I was co-opted to appear at the Dublin celebrations of that occasion. Having performed the song on stage with full band and backing singers, I was then summoned to meet with, and perform the song . . . a capella . . . for Winnie Mandela, who represented her husband on that occasion. A truly daunting task!

After the ban on the ANC was lifted, Mandela returned to its leadership and led his party in multi-party negotiations in 1990 and 1994, which led to South Africa's first multi-racial elections. He was elected as president of the ANC in 1991.

He and President F W de Klerk, were jointly awarded the Nobel Peace Prize in 1993, even though the relationship between the two was frequently strained. The country's first democratic elections were held in 1994, which the ANC won with 62% of the votes. This meant that Mandela was inaugurated as the country's first black president, with F W de Klerk as his first deputy, and he remained president until 1999.

During his time as president, Mandela presided over the transition from minority rule and apartheid, and he gained worldwide respect for his advocacy of reconciliation, with an aim of reconciling white and black South Africans.

Since he retired, one of his primary commitments has been to the fight against Aids, which one of his sons, Makgatho Mandela, died from in 2005. This was a son from his first marriage to Evelyn Ntoko Mase, with whom he had four children, one of whom died as a baby. His second wife was Winnie Mandela, with whom he had two daughters, and in 1998, he married his third wife, Graca Machel.

At age 89, Mandela is understandably older and frailer these days, and is not seen out in public too frequently. He was treated for prostate cancer in 2001, and announced his retirement from public life in 2004.

I always think of all Mandela did on behalf of his people when I sing 'Lion in a Cage' and remember one amusing occasion when an elderly lady approached me in a local supermarket, and said "Fair play to ye, a-girleen, ye got him out!" No amount of explanation would deter the woman from her opinion that I had singlehandedly achieved that result. I would not lay claim to any major role in gaining Mandela's release, but I remain proud to this day to have been able to raise my voice in support of such a worthy man.