Of course it's sacrilege, but in a country where rugby is far more important than religion, and where the faithful had seen their icons smashed to bits, Henry's crusade has created a revivalist fervour in which the term miracle worker is regarded by many in the Principality as perfectly reasonable.
Henry, being a New Zealander and therefore a pragmatist, is bemused by the recognition. "I try to stay away from the hype," he said, while his every word and action was being filmed and recorded for a BBC Wales TV documentary. "I don't go to the supermarket any more. I can't do any shopping, because of the attention. I knew rugby was important to the Welsh, but I had no idea of the magnitude. The whole state of the nation depends on the performance of the team. It's ludicrous."
This time last year Welsh rugby was a joke. In Pretoria the crowd was screaming for South Africa to put 100 points on the board; the Springboks disappointed them, beating Wales 96-13. Wales, once so dominant, so skilful, so cocky, were now so out of touch, so humiliated, so broken. The Welsh Rugby Union, largely held responsible for overseeing the destruction of a country's heritage, signed a provincial coach from New Zealand who had never played for or coached the All Blacks.
Last week an almost miraculous conversion took place at the Millennium Stadium in Cardiff, where Wales beat the Springboks 29-19. The match to mark the opening of the most impressive building in Wales since Caernarfon Castle coincided with the most extraordinary victory. Apart from plastering the walls of the dressing-room with one word - tackle - Henry reminded his players of something else. He told them: "We are the number one motivating force for the Welsh nation. That is our responsibility."
Since the countries first met in 1906, Wales had never won, a 6-6 draw at the old Cardiff Arms Park in 1970 being their best result. The Springboks had scored 282 points to 91, 41 tries to seven. And then they opened the Millennium Stadium. "Grown men had tears in their eyes," Henry said. "They told me that now they could die happy."
Dai Happy would be a suitable name for the mascot for the World Cup which kicks off on 1 October, when Wales play Argentina in Cardiff. The triumph over the world champions has not only reawakened the Welsh choirs, but was also convincing enough to persuade even a neutral that Wales could have a serious tilt at the game's greatest prize. "That's fairy tale stuff," Henry said. "Wales can't win the World Cup, because they are not good enough."
He has been preaching caution at every turn but Dai Happy has reached the point where he is prepared to beg, steal and borrow to get a World Cup seat in the Millennium Stadium.
Under Henry's reign, Wales began by running South Africa very close at Wembley last November. After beating Argentina at Llanelli (where the Welsh forwards were pushed from one end of Stradey Park to the other), Wales got off to a shocker in the Five Nations, losing to Scotland and Ireland. Then Henry got lucky.
Had France kicked a conversion in injury time in Paris, Wales would have lost by a point instead of winning by a point; had Scott Gibbs not scored an injury-time try against England at Wembley, Wales would not have won by a point. Instead of being whitewashed, the rebuilding programme was invested with steel. The historic win over South Africa was their sixth victory in a row.
Fine, but the Springboks were hardly at full strength and, as Henry pointed out: "We were lucky to get South Africa on the back of their 101- 0 win over Italy. It gave them an inflated opinion of their ability."
For all that, Henry is becoming more and more touched by developments and, a five-year pounds 250,000 contract aside, he is enjoying an equitable life. "At this point the team have surpassed my expectations," he said. "I have found the whole thing hugely stimulating. It's been a challenge, but I've been energised and motivated. I'd coached Auckland for seven years, some people thought it was such an easy job a donkey could do it. It was very important to me to show that I wasn't a donkey. I wanted the opportunity to prove that I could do the job at the highest level.
"It made me even more determined to get the best out of these people. When we played South Africa at Wembley the players were scared bloody stiff. They were on the edge of the edge, and there was a huge fear factor. You get worried that they're going to skin you. Playing in Cardiff was a major difference. When the stadium's finished it's going to be astronomical - as it was the noise was unbelievable. I watched the video on Sunday and I could hardly hear anything. I am very proud of what the players did. It was immense."
John Graham, the manager of the New Zealand cricket team, was invited to the match by Henry. "He rang me the next day and said it was one of the greatest sporting occasions he'd ever been to. His wife was thrown in the air by jubilant supporters. Wales is the most passionate rugby country in the world. They get a lot closer to the team and they bare their soul, although they were probably baring a few other things on Saturday. I wasn't sure what the potential of this team was and I didn't think we'd get this far this quickly. I thought we'd win a few Tests but to beat South Africa was a huge bonus."
The same weekend, the All Blacks demolished France, but Henry discovered that, on a national radio phone-in programme in Auckland, 70 per cent of the calls were about the Wales-South Africa match.
By unearthing the roots of a genetically modified family tree, Henry has made Welshmen out of a couple of Kiwis and sprang an even bigger surprise by naming the young Australian, Jason Jones-Hughes, in his World Cup squad. The Wallabies have taken the matter to the International Board. "Jason's father was a North Walian who went to Sydney 26 years ago," Henry said. "I have been talking to Jason off and on for months, and he wants to play for Wales."
Having experienced Wales's homecoming, Henry and his wife Raewyn took a flight to Auckland. On a 23-day trip he will mix family reunions with watching the cream of the Southern Hemisphere in the Tri-Nations. The TV documentary team, who until last week had few buyers for their film, will follow him. Henry will return with something to declare, his 18-year- old son Andrew, a promising centre and another potential convert. "I get the odd flicker of nostalgia," he admitted, "but coming to Wales was the best decision of my life. It's been a huge learning curve."
About the only thing he hasn't learned is the Welsh National Anthem. "I can say Llandaff but I need a teacher," said the former headmaster. So far, so miraculous.Reuse content