Prime Minister Stephen Harper (right) shares a laugh with former Prime Minister Brian Mulroney during a dinner hosted by the Ukrainian Embassy held in Mulroney's honor in Ottawa Wednesday, April 18, 2007. (Jonathan Hayward/Canadian Press)

When he stood up in Parliament earlier this week to announce a full public inquiry into the Brian Mulroney-Karlheinz Schreiber affair, what was Stephen Harper feeling about his Conservative predecessor?

Remorse, glee, betrayal, anger? We will probably never know. Not only is Harper one of the more emotionally contained party leaders to sit in the big chair, but his personal relationship with Brian Mulroney has been nothing short of a roller-coaster ride over the past two decades.

What began in admiration, for Harper at least, soon evolved into disappointment, mistrust, calculation and political seduction, according to what can be gleaned from public statements and the writings of biographers such as William Johnson (Stephen Harper and the Future of Canada) and Bob Plamondon (Full Circle: Death and Resurrection in Canadian Conservative Politics).

The same probably held true for Mulroney, who must have seen in Harper at one point the very antithesis of everything he held dear — the arch-Reformer who sharpened the lance that destroyed the Meech Lake accord and eventually the Progressive Conservative party and much of what it stood for.

Certainly, the two men are cut from different cloth. Harper is the epitome of buttoned-down and reticent. According to recent reports, he has been refusing to call influential Quebecers to urge them to join the party, saying that is not his role. Mulroney in power was the garrulous back-slapper who couldn't pass a telephone without reaching out and touching whoever was on his mind.

But there is also no question the two had grown closer in recent years. In April 2006, shortly after being sworn in as prime minister, Harper attended the function in which Mulroney was honoured as the greenest prime minister in living memory.

Just a few months later, the Mulroneys were the Harpers' guests at the prime ministerial retreat at Harrington Lake, which was when Mulroney was supposed to have passed on a letter from lobbyist Karlheinz Schreiber, if Schreiber is to be believed.

Harper has denied ever seeing such a letter and certainly his public affection for Mulroney did not noticeably abate in the months following that get-together.

As recently as April 2007, for example, Harper attended a gala at which Mulroney was being honoured by the Ukrainian Canadian Congress, where he called the former prime minister a real, effective leader who set clear goals while he was in office and remained true to them, "seeing them through against attacks motivated by misunderstanding, misinformation or just plain old political opportunism."

In reply, Mulroney went on at length about Harper's wife, Laureen, comparing her to his wife, Mila, and calling them both the best campaigners and advisers a prime minister could have.

It was quite a love-in. But it wasn't always thus.

The falling out

Stephen Harper was a 25-year-old university graduate working on Conservative Jim Hawkes Calgary campaign in 1984 when he first met Brian and Mila Mulroney. According to biographer William Johnson, Harper was tremendously impressed by both the personality and politics of Mulroney — so impressed, in fact, that he followed Hawkes to Ottawa a year later to be his executive assistant.

It didn't last. Just a year after that, in the fall of 1986, Harper left Ottawa, disillusioned by power politics and the Mulroney government's economic record, particularly as it affected Western Canada.

In 1987, two things happened that changed Harper's life dramatically: he met Preston Manning and the Meech Lake accord was introduced.

Over the next few years, Harper would become Manning's policy guy and speech writer, penning some of his leader's strongest lines against Meech, special status for Quebec, and Mulroney — indeed, virtually everything the Conservative government stood for. In 1988, he ran as a Reformer against his former boss, Jim Hawkes, and defeated him in Calgary West in 1993, the year the Tories were routed.

Harper eventually fell out with Manning over strategy and personnel decisions and left Reform in 1997 to head up the right-wing National Citizens Coalition, where he stayed until he returned to active politics in 2001 to run for the leadership of the Canadian Alliance.

From 1987 to 2001, it is safe to assume he had virtually no contact with Mulroney or key members of his faction.

When the Progressive Conservative leadership came open in 1998, Harper's name was occasionally bandied about as someone who might be thought of for the job. But he never expressed any public interest and the overtures came mostly from a ginger group associated with the far right of the PC party, not the so-called Red Tories, who were loyal to Mulroney.

Harper had written articles from time to time about uniting the right but his strategy seemed more a kind of reverse takeover.

When the first Canadian Alliance leadership came open in 2000, for example, Harper chose to support Ontario candidate Tom Long instead of fellow Albertan Stockwell Day, reasoning that if Long won (and could hold Alberta), an Ontario leader would eventually bleed the federal Tories dry.

The resurrection

Harper took over the Alliance leadership from Day in 2002 and did a very interesting thing: in his first speech as leader in the House of Commons, he praised Brian Mulroney. Not completely — he acknowledged he was not in favour of Mulroney's economic, social or constitutional policies.

But he told the Liberal government of the day that it had a big lesson to learn from Mulroney when it came to such things as free trade and Canada's relationship with the U.S.

In hindsight, it looks like Harper was sending out a smoke signal.

For the next year, he vigorously pursued a unite-the-right merger with the PCs, first (unsuccessfully) with Joe Clark and then with new leader Peter MacKay. In this, Mulroney played an essential role, most observers agree.

Whether Harper and Mulroney actually spoke directly during this period is not clear. But Mulroney emissaries certainly negotiated with Harper and Mulroney himself was influential in holding MacKay's feet to the fire and getting the deed done.

That said, though, it seems pretty clear that Harper was not Mulroney's choice to lead the united party.

Mulroney let it be known that he favoured Bernard Lord, then the bright young bilingual premier from New Brunswick. When Lord backed out, Mulroney seemed to be backing MacKay, whose father, Elmer, was one of Mulroney's closest confidantes.

Indeed, in the Conservative leadership race, MacKay and then Conservative Belinda Stronach appeared to have the lion's share of all the Quebec delegates, delegates who would have been largely part of the old Mulroney machine. Harper was forced to court outsider Mario Dumont of the Action Démocratique for his Quebec help.

In the end, of course, Harper won and a certain amount of fence-mending went on with all the important factions of the party. The Mulroney group was clearly one of them but the former PM took quite ill in 2005 and seemed to drift off the public radar.

The first hint that he was back in the game came late that year during the federal election that culminated with a Harper win in January 2006.

At one point on the campaign trail, Harper told reporters that he had been in contact fairly regularly with Brian Mulroney and valued his advice. For most of those covering the campaign, this was news. No one had even thought the two were on speaking terms.