One scrum during Saturday's match at the Millennium Stadium told you a lot about Wales. It gave a glimpse of why the team had risen from failure in the 2007 World Cup in France to triumph in the 2008 RBS Six Nations Championship and the grand slam.

The scrum came in the third quarter when France were in the Wales 22 and had the put-in after a series of fumbles by the home side. Though trailing 19-9, France could almost touch Wales's line. Seven points were within their reach, three the minimum they should have scored.

As the ball left the hands of Jean-Baptiste Elissalde, the France scrum half, the men in red gave one mighty heave and won a strike against the head. Seconds later the France pack was shoved off the ball. “That was the turning point,” Ryan Jones, the Wales captain, said. “That was the moment we recognised they had cracked.”

That scrum demonstrated how far Wales had come since last September. To understand what had happened along the way, one must return to the team's arrival at their hotel in Pornichet, a suburb of La Baule, in France. There were goats roaming the hotel grounds. Mark Jones, the son of a farmer in mid-Wales, rounded one up and put it in a team-mate's room. Early one morning players were woken by the noise of some of the management returning from dinner, singing.

Clearly all was not right and the process of change began within hours of Wales losing to Fiji on September 29. The Welsh Rugby Union (WRU), often considered to be ponderous and run by committees of elderly, outdated former players, moved swiftly. On the Sunday, when Wales should have been travelling on to Marseilles, Roger Lewis, the energetic group chief executive of the WRU, fired Gareth Jenkins, the head coach, and soon after led a team to the southern hemisphere to find a replacement.

Within weeks, they had their man in Warren Gatland and on January 14 Gatland announced he had persuaded Martyn Williams to come out of retirement, and from a long list of Joneses (Stephen, Alun-Wyn and Mark) chosen Ryan to be captain.

The New Zealander then set about remotivating Gavin Henson, whose private life was as colourful as the dye with which he is alleged to stain his legs. In December, en route to Wales, Gatland had said he welcomed the chance of dealing with Henson.

Henson has repaid Gatland's faith in him with a series of near faultless and selfless displays alongside Tom Shanklin. He has yet to play in a losing Wales team in the championship. Henson said: “I'd rather make a try for someone else than score one myself.”

Other achievements by Gatland in this period included getting Rob Howley to become the team's backs coach and retaining Neil Jenkins as the kicking coach, which seemed to have paid off when Wales landed 21 out of 21 kicks in their first three games.

Perhaps best of all, Gatland concocted a deal with Shaun Edwards to become Wales's defence coach without leaving London Wasps.

Yet it still took a measure of luck for Wales to win the first game of the championship after being 19-6 down to England at Twickenham. As Wales rallied before going on to triumph 26-19, the home team crumbled. “I had spoken to the coaching staff and said if we beat England we would have momentum and momentum is what wins an event like the Six Nations,” Gatland said. “Shaun said to me, “You Kiwis are all the same, eternal optimists. But I suppose you have to be.”

Mike Phillips was outstanding that day and his revitalised form may have been the work of Howley, who knew Phillips from their days together at Cardiff Blues. Howley persuaded Phillips to curb his attempts to run and to work on his box-kicking. The result was commanding performances against England, Scotland and France.

By now the Wales squad knew that Gatland liked short, sharp training sessions, so intense they resembled a game. This vigorous approach was in marked contrast to what had happened in France, when the players allegedly declined to do more than one contact session. The Wales players were acquiring huge respect too for Edwards, nominally the defence coach but also the heartbeat of the team with his unsmiling demeanour and will to win, underpinned by humanity.

Gatland had made no secret of the fact that he considered some players to be tubby and the entire team not to be strong or fit enough and in mid-February, the week before the game against Italy, Paul Stridgeon, a former wrestler and fitness coach at Warrington Wolves, was brought in to give Wales a beasting in the gym. The players were put in groups of four and did 25 minutes' non-stop exercise, mainly upper-body work. It was the hardest thing any of them had ever done. “I never want to see that man again,” Shanklin said. “Never, never, never.”

Wales's newfound fitness levels were evident in the first half against Italy, when they softened up the vaunted front row of the visiting team by hard scrummaging and continually moving the ball across field, keeping the tiring Italians on the move. Leading 13-8 at half-time, Wales's extra fitness told in the next 40 minutes, when they scored four tries and 34 points.

Fitness also told when Wales played one quarter of the triple crown decider against Ireland with 14 men and it was needed for every one of the first 60 minutes against France.

By the end of Saturday's game, it became clear that a multitude of things had fallen into place in the previous six months. Most had been instigated by Gatland but more than might be expected had been achieved by the players. Almost every player had exceeded all previously known form, led by an inspiring captain in Jones and the record-breaking Shane Williams, who did not put a foot wrong in any of Wales's five games and scored six tries as well. The players never lost their belief in themselves. After all, the triumph in Cardiff was achieved by nine of the men who had been on the pitch against Fiji. Most of all, though, Saturday's tumultuous victory showed that the porkies of Pornichet had been turned into the strong men of Europe.