By Nick Assinder
Political Correspondent, BBC News website
In the early days of his leadership, Charles Kennedy had the unsettling habit of telling his troops it was all "downhill" from now on, or that this was "as good as it gets".
Mr Kennedy with new MPs in 2005
Undoubtedly, there were some in the Liberal Democrat ranks who feared that was just a bit too close to the truth.
After action man Ashdown had abseiled into the leaders' office, firing on all cylinders and setting a punishing pace for his colleagues, Mr Kennedy could not have been a bigger contrast.
His laid back, chatshow Charlie image was a worry to some in his party who - having probably not wanted him in the first place - started whispering even then about whether he was really up to the job.
How, they wondered, after Paddy had taken them to great electoral fortunes and even got them into a near-cabinet minister relationship with the government, could the relaxed Mr Kennedy match that, let alone better it.
In fact their new leader went on to prove them wrong and for six years took the Lib Dems from strength to strength.
For a start, his relaxed, approachable, one-of-us image appeared to find favour with the voters.
Time and again opinion polls showed he was perceived as the most trustworthy and straightforward of the political leaders.
The occasional stumble was more likely to be put down to the fact he was a normal, fallible human being rather than a party automaton.
Mr Kennedy has appeared on the BBC's Have I Got News for You
He also made some fundamental and hugely difficult political decisions.
He ended the relationship with Labour after suspecting it was turning into a trap rather than an opportunity - largely because Tony Blair failed to live up to his part of the bargain by offering a change in the electoral system.
And later, in by far the most controversial decision of his leadership, he led his party in outright opposition to the war on Iraq, something that saw the Lib Dems taking large numbers of votes from both Labour and the Tories.
Along the way he helped finally bury the old image of his party as a group of sandal-wearing, slightly barmy irrelevances, a process started by his predecessor.
At party conferences over the past couple of years, the Lib Dems were far more likely to attract headlines about "getting serious" than anything else.
Looking under pressure at the 2005 conference
He more or less abolished the old habit of his party conference passing controversial resolutions, on drugs and pornography for example, that inevitably attracted negative coverage.
And he certainly made it clear they would not be adopted as official policy, no small thing for the leader of a party that puts its members at the centre of decision making.
And, of course, he took his party to its most successful election performance for some 80 years.
But there were recent rumblings that a turning point had now been reached for the Liberal Democrats and many in the party believed they could and should have done better.
A debate over its future direction started to rage between the so-called social liberals and more right-wing appearing economic liberals.
These are two traditions from the old Liberal and Social Democrat parties that had provided a constant undercurrent of debate ever since the two merged.
But the election of new, young, ambitious Lib Dem MPs brought it into the open ¿ most notably with the publication of the Orange Book collection of essays from those advocating a more market oriented approach to the economy and public services.
Charles Kennedy with predecessor Paddy Ashdown
There was real potential here for the party to be split in two and it was one of Mr Kennedy's great strengths that he avoided that, largely by refusing to get drawn too deeply into it.
His critics saw his approach as a weakness and argued he was letting the party drift.
His biggest challenge, had he remained leader, would have been to finally resolve that issue.
And the question for the new leader is whether he or she will be able to do it without dividing the party down the middle.
The Kennedy years were undoubtedly good years for the Liberal Democrats and it is certain his leadership will be remembered not only with genuine affection by many, but respect for his achievements.
Part of the judgement on his performance may well be based on what happens to the Liberal Democrats now he has departed the leadership.
But whatever that judgement is, he will undoubtedly continue to be a major and influential figure in the party - in much in the way William Hague is now regarded in Tory circles.