Conor O'Shea first came across Stuart Lancaster as opposing players in 1996, when the former was a fullback for London Irish and the latter a backrower with Leeds. They were both employed by the RFU, O'Shea as the Director of Regional Academies from 2005 to '08, and Lancaster their Elite Rugby Director from '08 to '12. O'Shea was even part of the RFU appointments' committee and interview panel which chose Lancaster.

The erudite former Irish fullback turned Director of Rugby at Harlequins, and RTÉ pundit, knows Lancaster well and not only respects him but clearly likes him and believes he has done a superb rebuilding job after England's charmless and anti-climactic 2011 World Cup campaign.

“He’s a very straight down-the-line guy,” O’Shea says of the English head coach. “He’s very passionate about what he does, and is unbelievably well read. You talk about Joe (Schmidt) having that Mr Rugby nickname, and no one else will be called that, but Stuart has the same massive thirst for knowledge. He would go anywhere to learn something. But he’s a typical Yorkshire person. Head firmly on his shoulders. No ego, and expects other people to be like that.”

In personnel, in style and perhaps most of all in character, Lancaster has virtually remoulded the discredited English side he inherited from Martin Johnson into one mirroring his own hard-working and humble persona.

As a measure of the Lancaster revolution, only Dan Cole of the English side that beat Scotland last Saturday, and which will probably be retained to face Ireland next Saturday, started that fateful World Cup quarter-final defeat to France, while Dylan Hartley was a replacement that night. None of the rest of last Saturday's match-day 23 were involved in Johnson's final game.

Without them
Before his first Six Nations campaign he took some of the old guard out for a coffee and individually informed the likes of Nick Easter, Mike Tindall and Mark Cueto that he would be moving on without them. He picked eight debutants in his first match-day 23.

Not all of them worked out, and England rode their luck with narrow away wins to Scotland and Italy thanks, in each instance, to blockdown tries by Charlie Hodgson, but his stand-in role has evolved into a permanent role.

He has retained the services of Andy Farrell, Graham Rowntree and Mike Catt, and a new, younger team with one eye on hosting the 2015 World Cup have progressed impressively. They have beaten the All Blacks, drawn a third Test in South Africa on the day Ireland lost 60-0 in New Zealand, and won 10 of their dozen Six Nations game under Lancaster’s watch, their only defeats being to Wales.

“He’s been outstanding, too, in his relationship with the clubs,” says O’Shea from personal experience, “and building that trust. His communication is second to none. At times you’d almost tell him not to ring you because he’d ring you an hour and a half after an international to give you a quick update. That’s just the way he is.”

Certain characters and egos have not been accommodated, the fractious cliques along Leicester/Saracens/Harlequins lines have been done away with, and the players clearly like him. He’s helped revive their English rugby heritage, yet have become a more open, media friendly group as well.

Another benchmark appointment in this process was emulating O'Shea's choice of Chris Robshaw as captain at Harlequins. "He went for him for the reasons I went for him," says O'Shea. "He's not Winston Churchill. Doesn't want to be ever seen like that. He works harder than any other player.

'On the chin'
"He's always taken disappointment on the chin and come back stronger for it, and that goes the whole way back in his life. His dad died when he was young. He had a 'career-ending injury'. He's always had adversity, like not being picked for the 2011 World Cup, when I was championing him. And I championed him for the Lions.

“He never really gets the credit that he deserves. It’s always begrudging. He’s a hard worker, and he’ll have his ups and downs, but that’s why he’s captain, because you follow him, and you want people to be like him.”

Lancaster has also sought to give this England team an identity which he evidently felt had been lacking, and which he felt the Celtic nations have more innately, not least when they play England. The home dressing-room at Twickenham underwent a redesign, with each designated seat engraved with the names of celebrated predecessors.

The first home game under his watch was a 19-12 defeat to Wales, but that was followed three weeks later by the scrum-based 30-9 rout of Ireland and in November 2012 England kick-started a six-game, year-long winning run at the venue with a stunning 38-21 win over New Zealand, a sequence which the All Blacks brought to a halt last November.

“It’s a hugely positive factor for me,” Lancaster said of the Twickenham factor this week. “I got asked in interview ‘did you feel the atmosphere? It was a bit quiet out there’. I’ve never experienced that. Maybe it’s just me, because you feel the pressure of the game but Twickenham has been great for us, we’ve trained there a lot more than in the past, it feels a lot more like home.

“Having the pitch done means there is a bit more flexibility from the groundstaff. More importantly, the changing room, the history behind it, the things we’ve done and the experiences we’ve had there, means the players enjoy going back there. And the Twickenham crowd has been brilliant behind us.

"One of the players said at the weekend that it adds 20 per cent on the performance, and I agree with that."

Biggest threat
O'Shea lists the current English pack and those on the fringes, along with their age profile, and nominates the hard-carrying close-in game of Billy Vunipola, Dylan Hartley, Joe Marler, Chris Robshaw, Tom Wood, Courtney Lawes et al as the biggest threat to Ireland.

“They can all carry and if they allow Billy Vunipola over the gain line, and if you get Danny Care on the front foot, they’ve some dangerous runners. It’s a big fearsome unit of a pack with huge potential and it will be a really interesting battle because the Irish pack will be so strong. You look at that young frontrow that can come on with no (Richardt) Strauss, I think both countries are in really rude health in terms of what they’ve got.”

In that regard England are as much a team of the future as the present, albeit injuries and changes have obliged Lancaster to run with an inexperienced backline, with Johnny May, Jack Nowell and Luther Burrell set to win their third caps next Saturday.

O’Shea also sees clear evidence of England broadening their game. “What I’ve been most impressed with England this year is their attacking game, which I think has come on a mile.”

Key to this has been allowing O’Shea’s own Harlequins scrumhalf, Danny Care, “the licence to do what he does as opposed to restricting him. He’s thriving and the balance between him and Owen Farrell looks really good. They’ve got loads of numbers coming around the corner. I think they’ve improved their attacking threat. I’m not saying they’re the finished article, but they’ve definitely moved their game on massively this year”.

O'Shea cites Care's tapped penalty which led to Mike Brown's game-turning try in Paris, which if it had ended in a try, would have led to Care being villified. "But Danny has reached the stage where he understands that, and that it is the risk he takes. We talk a lot about 'super strengths' (at Harlequins) and being who you are, and I said to Danny 'you go ahead and be you, as opposed to trying to impersonate the guy that people want you to be, because you're good enough. Don't fail by trying to be someone else'. Danny has had his fair share of self-imposed knocks, and at 27 I think he's just mature."

Feisty character
Brown is a very feisty character on the pitch. "He's a competitor. Is he feisty? Yes. Is he completely different off the pitch? Yes, completely. But I've always liked left-footed fullbacks. When we played Munster a few years back in Thomond and I remember Quinny (Alan Quinlan) saying to me 'I'd love him to be playing for Munster'. In a weird way it was the ultimate compliment."

The 23-year-old Harlequins and England loosehead, Joe Marler, “is another spikey individual” according to O’Shea, who takes particular umbrage over the criticism Marler received after the defeat to Wales last year when Adam Jones “got away with a few things”.

“This kid is learning all the time and I think he’s going to become one of the most ferocious players in world rugby because he’s athletic, he’s got great footballing ability and like Cian Healy is the prototype for the modern day loosehead. And he’s got a really, really dry sense of humour. Joe hates me saying it but I think there’s a bit of Irishness in him and he could have played for Ireland.”

Clearly relishing the thought of next Saturday’s game already, O’Shea pinpoints Johnny May as a particular threat. “He doesn’t know where he’s running half the time himself, and he admits it himself, but God almighty he’s quick, and he’ll cause problems for anybody if he gets any sort of opportunity in broken field. But knowing Joe, he will target the England inexperience because the English defence is so suffocating that they’ll be quite narrow. But if you run directly at them, a bit like Wales, that’s just manna from heaven.”

Although O’Shea will have vested interests in both camps, there are no divided loyalties. He’ll text his four Quins players good luck messages, “but they won’t believe me”. He wants them to do brilliantly, but not win.

“It’s an interesting challenge for Joe, because it’s his first away game as an international coach, but he’s got enough experienced people around him. Home advantage does count, but home in London tends to get blurred when the Irish manage to get a hold of tickets.

“It’s so blooming close. I think this English team are playing well. They should have beaten France comfortably and this Irish team are in a fabulous place, and Peter O’Mahony is playing rugby you’d dream of. Is it a one-score game? It is. I think no matter what, Ireland have almost done enough to win the championship because I think they’ll beat Italy at home and can win in France.

“So I think it’s down to this game and if they win this game I don’t see anyone stopping the Grand Slam. I know that’s a weird thing to say after two games. But this is the big one.”