Justin Welby was deeply impressed by the reconciliation work of the Revd Andrew White, the Canon for Reconciliation Ministry at Coventry Cathedral. In January 2002, this led to the signing of the Alexandria Declaration, which brought together Christians, Jews, and Muslims in the Middle East.

Welby wrote to congratulate White on his extraordinary achievement, promised the fervent prayers of Southam parish (the small market town where he was then Rector), and hoped that he might travel with White on one of his excursions, "as bag carrier or anything".

White promptly invited Welby to Israel and Palestine in March 2002, on a follow-up visit working towards the implementation of the Alexandria Process. The adventure was, for Welby, "a mind-blowing, viewpoint-changing, memory-charging experience".

Welby's abiding impression was of hearing the stories of desperate and fearful people, both Israeli and Palestinian, who longed for peace. He encountered Orthodox Christians from Bethlehem who, despite poverty and persecution, spoke confidently of their hope in Christ. The Rector of Southam was left pondering that "It puts the issues of my life and work in perspective."

Shortly afterwards, Welby was invited to join the team at Coventry Cathedral as White's co-director of international ministry. When offering him the job, the Bishop of Coventry, the Rt Revd Colin Bennetts, explained that he would spend two weeks a month travelling, mostly to areas of violent conflict, and would have to raise his own finances. Caroline, Welby's wife, said that "such a crazy offer could only be from God," and so had to be accepted.

Welby and White forged a good working relationship, and a strong personal friendship, and Welby brought to the team particular experience in management and finance.

He left Southam in October 2002, and was installed the following month as a Residentiary Canon. Welby focused on Africa, especially Nigeria, where he had first travelled with the oil company Elf Aquitaine in the late 1970s.

After riots in Plateau State, centred on Jos, the state governor asked Welby and his Coventry team to facilitate community reconciliation in 2003. They commissioned research into the root causes of the violence through the Centre for Conflict Management and Peace Studies at the University of Jos.

They organised peace-building and skill-training workshops for more than 1000 disaffected Christian and Muslim youths. In collaboration with the state security services, they financed an early-warning system in the form of satellite telephones for key community leaders across the religious and ethnic divide, to enable quick communication in the event of crisis. Because newspapers were often complicit in escalating violence, they also gathered journalists from ten states across central Nigeria to teach how the media can alleviate rather than aggravate tensions.

In the south of the country, in the Niger Delta, Welby was invited by the Nigerian government to act as an international mediator for its peace and security strategy, bringing together indigenous communities, oil companies, and local officials.

Although Welby had witnessed much abject poverty during his African travels, in the swamps of the Niger Delta he saw "poverty unlike anything I had seen before".

Much of Welby's work in Nigeria, Burundi, and elsewhere placed him in positions of grave personal danger. On a dozen occasions, he found himself in situations where the militia was in control, and anything might happen. Twice from Nigeria he telephoned Caroline at home in Coventry, and asked her to pray, fearing that he might have miscalculated the risks, and might be dead within minutes.

At the height of the violence in Plateau State in 2004, Welby drove in convoy with an armed escort to Wase, a Muslim-controlled town about two hours from Jos. In a tense atmosphere, as he was meeting the local emir, his Muslim driver outside overheard three young men with AK47s discussing whether to kill their English visitor. They left in a hurry.

On another occasion, Welby was taken out to dinner in a hotel at Port Harcourt by a Nigerian oil contractor involved in bunkering (stealing illegally produced oil) and given subtle death threats at the table. He learnt that he had a price of $30 on his head, and later joked that, in comparison with the $250,000 contract to kill Andrew White in Iraq, "I couldn't decide whether to be insulted or afraid." But he quickly left the area.

Welby admitted that the reconciliation ministry was "dependent upon very large donations from a very few sources". In 2005, the work collapsed.

The cathedral's international ministry was downsized, and there was a change of focus, away from flak-jackets and dodging bullets in war zones to reconciliation at home. Since the funding had run out, all the employees at the International Centre for Reconciliation (ICR) were made redundant. Welby was moved to the domestic side of the cathedral's ministry, although he was allowed to continue with some African visits much less frequently.

The collapse of the ICR and the dismissal of staff was a major knock-back, for which Welby felt personally responsible, an emotionally draining episode. He called it an "experience of grief", and reflected:

. . . the pressures of achievement, or working towards targets, or trying to get things done, are the ones that knock us off course. I had a significant failure this autumn, and struggled profoundly, emotionally, in terms of stress and trying to know what to do. At times like that, and just as much in the pressure of success, we can find we are no longer the people we want to be or even feel comfortable being. My aim for 2006 is to keep my core values in the centre of what I do, and maintain the boundaries that tell me where I am going wrong.

Within the Coventry Cathedral chapter, there was a "full and frank exchange of views" about homosexuality, after Canon Jeffrey John withdrew his acceptance of the post of Bishop of Reading. Welby asked, "How can we go around the world trying to talk about reconciliation . . . when we don't live it out in our own community?"

Welby made his own position clear, writing that "sexual practice is for marriage, and marriage is between men and women, and that's the biblical position." Such a view was pastorally difficult, "but it's what the Bible says". Therefore, the question of right and wrong in the Jeffrey John affair "matters enormously . . . truth is essential."

None the less, he was perturbed at the manner in which Canon John's nomination as a bishop was debated by the Church: "the public arguing through the columns of The Times, the Telegraph and over the BBC has not helped evangelism. . . I'm not saying that the issue isn't important: it's just not the right way of doing it."

He reiterated that, whatever people might think about the principles at stake, "it cannot be right that the secular press is a substitute for dialogue between Christians, a vitriolic go-between that makes our communication with other people who follow Christ more difficult, not more easy."

He lamented that the Church of England's "destructive" arguments over homosexuality were "a diversion of effort", a distraction from the task of "seeking to win the 92 per cent of this population who never go near a church and find the whole debate completely incomprehensible". Nothing, he warned, was "a greater sapper of spiritual passion" than public division.

At Coventry Cathedral, the Dean, the Very Revd John Irvine, created space for "an open conversation" about homosexuality during a Sunday-evening service in spring 2004. Welby debated the issue with his friend, the Revd Adrian Daffern (the Canon Precentor), seeking to model to the congregation a generous and prayerful approach to theological dialogue in a spirit of harmony.

After the event, Welby reflected: "in God's grace we managed to disagree profoundly, but without bitterness, without rancour. I cannot deny he's a Christian: he loves the Lord Jesus Christ. I disagree profoundly with some of his interpretation of scripture and am quite happy to say so in public," but their conversation had taken "the sting out of the debate", and "had an immense effect in bringing people towards Jesus Christ".

WELBY first encountered Anglican Benedictines as an ordinand in the early 1990s, when he spent four days on retreat at Elmore Abbey, near Newbury, in Berkshire, at the recommendation of his stepfather, Lord Williams of Elvel.

During his first retreat, Welby found the liturgical rigour of the community difficult to cope with, "the regularity, the vast chunks of psalms, the lack of spontaneous worship". But he soon came to find the discipline a help:

There are also moments of awe, as through sheer repetition the word of God penetrates my thick skull, and I see afresh. Above all, for me, there is the encouragement of ordinary people seeking to live out a life of integrity in community, with Christ at the centre, guided by a Rule of incandescent common sense.

Welby was a regular visitor to Elmore, and in 2004 became a Benedictine oblate (similar to the "third order" among the Franciscans and Dominicans), committing himself to following Benedict's Rule in his daily life. To his parishioners, he explained that the Rule was "full of good stuff" and remarkably contemporary as an antidote to stress.

He pointed especially to Benedict's emphasis on a balanced lifestyle (a mixture of work, prayer, and rest), stable relation- ships, and freedom from chasing after possessions.

He also later noted Benedict's counter-cultural emphasis on obedience: "I am very challenged by it. As a canon, I have sworn obedience to the Queen, the Bishop, and the Dean (the last two with explicit qualifications!). . . I don't do obedience very well. Nor do many people."

Yet he admitted that obedience to those in authority was essential for the flourishing of a Christian community, and a reflection of their obedience to God.

These are edited extracts from  Archbishop Justin Welby: The road to Canterbury by Andrew Atherstone. It is published this week by DLT at £7.99 (CT Bookshop £7.20 Use code CT618 ); 978-0-232-52994-4.