The official retirement of Archbishop Desmond Tutu reminds us of what leadership motivated by morality and justice can accomplish.

In an age when the word 'leader' is used to describe everyone from a middle manager to a trade union organiser, it's almost too easy to forget that there are still people whose leadership has been crucial to literally millions of lives.

While the story of South Africa's struggle from the shackles of apartheid includes stories, told and untold, of heroism, sacrifice and pain; only one person has earned the accolade of 'the conscience of South Africa'.

The Nobel Peace Prize Laureate, Archbishop Emeritus Desmond Tutu, who announced his retirement from public life on his 79th birthday during October, is arguably one of the most important leaders in 20th century Africa.

From his days as a young clerk voicing his opposition to white minority rule to his chairmanship of the Truth and Reconciliation Committee and beyond, Archbishop Tutu has been central to the story of South Africa's political emancipation. Yet despite the enormous influence he has wielded, he appears to be a man whose feet remain in close touch with the ground.

In announcing his retirement, he is quoted by the South African Press Association as saying: "I have got a wife and family that help to keep my head the right size. Just when I am thinking that I am the cat's whiskers, they remind me that, 'you are just daddy for us and husband'."

I once had the privilege of listening to a sermon delivered by Archbishop Tutu and experienced at first hand his gift for taking his audience from tears to laughter and back again. His ability to deliver the most insightful observations, with his infectious chuckle removing any sting, left his audience feeling inspired to be and to do better.

Beyond the ability to inspire, any leader worth his or her salt needs courage in spades and this is a quality Desmond Tutu has shown throughout his life.

He came to international prominence after famously striding into a lynch mob about to take action against a suspected undercover policeman, calling for peace and calm. Although small in stature, he has never been anything but a giant in his willingness to confront injustice and to say what needs to be said to end conflict and to bring healing.

Whether during or post apartheid South Africa, Archbishop Tutu has continued to serve his ordained mission to fight for the poor, the weak and the vulnerable and to demand that political leaders act not in search of votes, but in a quest for justice.

When, in 1975, Desmond Tutu became the first black man to be appointed Dean of St Mary's Anglican Cathedral in Johannesburg, he used his pulpit and his travel privileges to condemn the atrocities taking place in South Africa and to encourage and promote sanctions against South Africa so that at least the suffering Black victims of apartheid would be suffering "with a purpose".

Despite sometimes violent attempts to silence him, Tutu's impact was such that disinvestment and sanctions did eventually come about. Two years after winning the Nobel Peace Prize in 1984, so did his appointment as Archbishop of Cape Town.

Desmond Tutu's influence has been felt in conflict resolutions not just in his beloved South Africa and across the African continent, but in many other countries including Northern Ireland. In 2006 he visited the country for a series of TV programmes that brought victims and perpetrators of violence together, including loyalist mass killer Michael Stone.

Creating a more equitable society and ensuring a wider distribution of wealth, the Archbishop once said during an interview in London with Niall Fitzgerald, then Chairman of Reuters, is critical in order to dampen the 'powder keg of poverty'.

Creating a more equitable society and committing to the African concept of 'ubuntu' with its emphasis on tolerance, forgiveness and our interdependence as people, is necessary to secure everyone's future, he says.

"It is in the interests of those of us who are well-to-do to see to the interests of others. Otherwise, we may not have anything at all."

Every human being, the Archbishop reminded us, is a 'God-carrier' and fundamentally good. "There isn't anyone who is a lost cause really," he once said, "although sometimes you have to look hard!"

For the man who coined the phrase 'the rainbow nation', his unswerving faith in the essential goodness of mankind - despite our capacity for evil - was not diminished by the horrors of apartheid and his infectious optimism is an indispensable part of what has made him such a superb leader.

"We have this remarkable capacity for good – all of us! We are made for goodness and it is something that we need to hear," he once said.

The Archbishop is not one to hide his emotions. Indeed, who can forget the tears he shed during the harrowing testimony of the Truth and Reconciliation Committee which he chaired during the early 1990's? But, as a true leader, he also acknowledged when giving into his emotions was becoming a distraction, and he vowed to stop breaking down when his tears threatened to become more of a story than those being related in the witness box.

Humour, self-deprecation and faith are all hallmarks of Archbishop Tutu's style of leadership. But even his status and staunch faith do not hold him back from some acerbic observations about religion.

"We Christians need to get off our high horse and learn to be a bit more humble" he said during the Reuters interview in London, dismissing stereotypes about religion as the product of "lazy thinking" and pointing out that as "Christians were responsible for the holocaust and for apartheid – we have to tread softly!'

He is secure enough in his faith to jest about how that faith came about. He famously once said: "When the missionaries came, they had the Bible and we had the land. And they said: 'Close your eyes and let us pray'. And we dutifully did so, but when we said 'Amen' and opened them, we had the Bible and they had the land."

But, all told, he admits that 'it was not such a bad deal.'

Like Nelson Mandela, the Archbishop has no time for those who would idealise him, finding stereotypes such as 'hero' and 'saint' to be pretty unhelpful in understanding the true nature of prayer, struggle and transformation.

A laudable sentiment, but it is hard to think of many people who better deserve to be considered as an icon for all that is good in Africa.

Archbishop Tutu says that with his retirement, his intention is not only to watch sports, spend time with his beloved wife Leah and, in his own words to 'shut up'; but also to make room for a new generation of leaders.

Although small in size, he leaves behind footprints that are almost too impossibly huge to fill.

The Archbishop has been called highly political but deeply spiritual. And, by exiting from the public stage, Desmond Tutu offers a challenge and an opportunity for others to lead in his stead; a challenge that Africans can only hope will be taken up by those who recognise morality not as old-fashioned or negotiable, but as an indispensable guide to creating a fair and compassionate society.

Click here to read 'An Evening of Healing with Archbishop Tutu'