HERE is a unique book about Nelson Mandela — not about the statesman or the prisoner, just about his relationship with his grandson.

The story starts when the Old Man (the author’s normal title for his grandfather) rescues the 12-year-old Ndaba from a dysfunctional family scene, and from the violence of Soweto. He gives him accommodation in his own home in Houghton, the secluded inner suburb of Johannesburg.

Ndaba was not an easy guest: he was something of a tearaway in behaviour, and undisciplined as a scholar. The Old Man was almost obsessive about orderliness; for him, this was part of self-respect. So, even when he was busy with his presidential duties, he tried to steer the wayward teenager towards an orderly lifestyle. He could unleash a powerful anger; Ndaba occasionally felt its lash, although this was normally reserved for people such as George W. Bush.

But Ndaba was learning all the time. He learned from his grandfather the biblical doctrine that forgiveness is primarily an economic principle, a practical strategy, especially in relation to debt and to land-tenure.

In Xhosa terms, “Going to the mountain” means the three-week retreat of study and initiation which is conventionally called the “circumcision school”, whereby a male adolescent becomes an adult. For Ndaba, aged 21, the time for this experience eventually arrived. He describes it in rare detail. But, after it, he is truly recognised as a man. Hitherto, his grandfather had always spoken with him in English. But now they talk in the language of their people, in isiXhosa. One of the beauties of this book is the wealth of Xhosa proverbs that are quoted, and the folklore stories, of which the Old Man was a master.

The President had retired; but, in his domestic world, there were crises that tested the Old Man’s diplomatic and personal principles in the sharpest ways. The grandson emerges as a man who begins to develop those principles on his own account.

This book is a precious example of inner history; it is a unique insight into a world-spanning person who was also a young man’s grandad.

The Rt Revd John D. Davies was a rural priest and a university chaplain in South Africa from 1956 to 1970.

Going to the Mountain: Life lessons from my grandfather, Nelson Mandela
Ndaba Mandela
Hutchinson £14.99
(978-1-786-33155-7)
Church Times Bookshop £13.50