Just over a year ago Stuart Lancaster’s world fell apart and judging by his expression as England exited their own World Cup before the knock-out stages you would have got long odds on him smiling in the foreseeable future. But happily for one of rugby’s good guys the grin is back and it is Irish eyes that are smiling too.

The 47-year old packed his rucksack after leaving the England job and has had roles with the Football Association, Atlanta Falcons, had a chat with the British Cycling, and Counties Manukau in the Mitre 10 Cup in New Zealand.

Now Lancaster is back in a tracksuit, doing what he likes most, coaching and not having to do with all the associated stuff that comes with being an international coach. At Leinster, who he joined in September, his title is senior coach – Leo Cullen is head coach, and after four years of dealing with sponsors, media, clubs and trying to run a Test team.

Back on the paddock: Lancaster has some top-quality to work with at Leinster

It suits Leinster just fine too – they are level on points with Munster at the top of the PRO12 – and the Cumbrian is coaching a large chunk of the best Irish talent on a daily basis.

“One thing I wanted to clarify before I committed to the role was what is the role?” said Lancaster. “I am very much hands-on coaching. A lot of the bigger picture stuff like selection calls are Leo’s as is the relationship with Ireland Rugby and recruitment.

“For me it’s more hands-on coaching with attack and defence. Girvan Dempsey would do the backs and John Fogarty does the scrum and I do the rest which is a change from the England role which was more of the bigger picture.

“I am really enjoying it and just to be able to think about training sessions, how to evolve defence and attack and to see progress. There are a group of talented players here, 13 played for Ireland not so long ago. It helps because we have a similar defensive system to Ireland – Andy Farrell and I know each other very well – and the team were coached by Joe Schmidt and Matt O’Connor so they have a good framework in attack and I’ve tried to add my own personality to it.”

Crossing paths: Leinster and Andy Farrell’s share the same defensive pattern

Lancaster was seen as damaged goods after the World Cup but the RFU missed a trick by not keeping him on in some capacity. No-one, after his years at Twickenham in various guises, knows more about the up-and-coming talent in England and there must have been a job for him somewhere in the building.

It would not have been like a new Manchester United office having Sir Alex Ferguson in the office next door and, as Lancaster has virtually no ego, he would not have ruffled any feathers with his successor as top dog with the senior team.

But once that die was cast Lancaster had to rebuild his reputation and the last couple of months have done a bit of that, helped by the fact that he has got some decent players to work with in Dublin.

“As a coach you always have to prove yourself,” he said. “I’m certainly having to prove myself to players here. These players are top end players who have been coached by some very good coaches. That’s what drives me more than anything else.

The main man: Lancaster has been impressed by Eddie Jones’ impact

“I don’t miss certain parts of the (head coach) job and I do enjoy being back coaching again. We’ll see. I’m pretty open-minded about the future. It’s been a great move to come back into a top-end European club. Great players – but I’ve learned now not to plan too far ahead.”

When England made it 14 wins in a row, 13 under Eddie Jones and one under Lancaster, with their 37-21 victory over Australia, Jones was quick to credit the work that his predecessor had done in unearthing a decent group of players. The current all-conquering squad is basically the same one that crashed out of the World Cup, with one or two tweaks, and it would be strange man who did not feel some regret about watching his former charges beat all-comers in the last 12 months. But Lancaster, who is now renting a flat in Dublin, does not do regret.

On the front foot: Lancaster has been unsurprised by England’s form

“Very few international teams have been on that sort of winning run,” he added. “It’s fantastic really, but in terms of success, I’m not surprised. Because the I know the team and know how good the players are. I think the credit goes to Eddie and his coaches and they have done a brilliant job in getting the best out of a very experienced team.

“When the World Cup came we had about 450 caps in the starting side – now it’s about 600-700 with an average age of 25. I always said that the new phase of England rugby would be successful. But nothing happens by chance and the coaches, and in particular Eddie, deserve the credit for that.

“Good luck to them for the Six Nations, I know from working over here how competitive that Six Nations programme is going to be. Being in Ireland now, all roads are leading to the Aviva on St Patrick’s Day. It will be some Six Nations, which is great for the competition, but also for the Lions.”