KEY POINTS:
When John Key moves into the Beehive, the least experienced Prime Minister in a century will have a man behind him who has been there before.
Wayne Eagleson, National's chief of staff for the past three years, will fill the seat held for the past nine years by the formidable but camera-shy Heather Simpson.
Known colloquially as H2, Ms Simpson worked in the backroom behind Prime Minister Helen Clark, negotiating, plotting a course through trouble, and frightening staff into action.
Mr Eagleson will take the reins behind Mr Key with a less fearsome reputation but with the loyalty of his staff and the strong backing of the new Prime Minister, with whom he has a close relationship.
One staff member described Mr Eagleson as affable and with a "totally different" style to what is publicly known about Ms Simpson.
"He expects, but he's pleasant to deal with."
Mr Eagleson did not want to be interviewed for this article, preferring to stay out of the spotlight.
As chief of staff he will be a fulcrum between National and other parties, acting as a chief executive of the Prime Minister's Office with hiring and firing responsibilities.
Mr Eagleson was deeply involved in National's successful election campaign and knows the party's strategies and inner workings.
When he steps into the Beehive he will also bring useful knowledge of how a previous National Government operated - he was a private secretary and adviser to former Prime Minister Jim Bolger.
He has a long history with the National Party, starting his career in its research unit before beginning to climb through the ranks.
One of the former colleagues who worked with him during the Bolger years describes Mr Eagleson as "very focused, affable, and quite a good listener".
"He looks to put good people around him - he doesn't have a problem with that," the former colleague said. "He will run a different style to what Heather did."
Calls to Mr Eagleson are met with an upbeat greeting even when things go wrong those around him say he maintains an approachable manner.
One such time was when then leader of National, Don Brash, had a horror week in May of 2006.
Dr Brash went into a press conference under-prepared and then walked the plank in a badly planned photo opportunity at a time when his leadership was in question.
Rumour has it Mr Eagleson offered his resignation after the PR disaster but he has preferred not to discuss that publicly. But if the story is true, the resignation was not accepted.
Mr Key, too, had confidence in Mr Eagleson and kept him on as chief of staff when he took over the leadership of National.
Mr Eagleson's background is not confined purely to the public sector.
He left Parliament for a time and worked in public affairs companies and for DB Breweries, Westpac and Transpower - from which Dr enticed him back to National..
WAYNE EAGLESON
* Forty-four years old.
* Two daughters, aged 9 and 6.
* Degrees in law, political science, history.
* Began his career in National's research unit.
* Worked in office of former Prime Minister Jim Bolger.
* Experienced in private sector public affairs roles in banking, energy, brewing.
* Rejoined National in 2005 when hired as chief of staff by Don Brash.
* Enjoys golf.