He took over as leader of the Social and Liberal Democrats in July 1988, amid the wreckage of the Alliance break-up after the 1987 election. He left it last night with his goal of a realignment of the centre and left in British politics tantalisingly within its grasp.
He is also by a long way the longest-standing party leader in Britain, having outstayed two Labour leaders and two Tory ones in his 101/2 years in office.
Mr Ashdown is an action man-turned-politician who has never quite lost the boyish excitement and bravado that led him into the Royal Marines at the age of 18, after he left Bedford School in 1959. A member of the Special Boat Squadron, and of MI6 (though he has never admitted it) between 1971 and 1976, he spent almost all his active political life as a Liberal, apart from one brief period as a Labour Party member when he was in the Army.
He is also one of the few serious politicians to have worked actively, as a labourer, as a personnel manager in industry, and as a youth officer for Dorset county council before he became an MP.
He took over his party at probably the most unpromising period in its history, and led it through an election in 1997 which secured it 46 seats, the biggest total since the 1929 election.
When he took over in 1988, the hopes and dreams of the Alliance - the uneasy marriage between the Liberals and the Social Democratic Party, which was supposed to replace the Labour Party as the main anti-Tory force in British politics - had collapsed in recrimination. The party he was taking over had become a joke - memorably dismissed by Margaret Thatcher two years after Mr Ashdown took over as a "dead parrot". In November 1989 it was still languishing in the opinion polls, recording a mere 3 per cent.
Mr Ashdown himself was forced swiftly to abandon the hopelessly ambitious vision with which he successfully fought his leadership election against Alan Beith in 1988 - that of replacing the Labour Party as the main party of opposition to Mrs Thatcher. But he patiently and steadily rebuilt the party over the next seven years by establishing a clear identity for it - and even more for himself. Familiarity might have bred contempt, and for many commentators it did. But after nine years as leader he still managed to score, during the 1997 election, a 58 per cent satisfaction rating - unheard of for an opposition leader.
But the more distinctive achievement was to set his party a clear strategy for dealing with Labour, for seeing that politics was about power and not posturing, and coaxing his members towards the sort of accommodation with Labour that stood most chance of achieving their most cherished objectives.
Many leading Liberal Democrats were deeply uneasy about this strategy, as the forthcoming contest to replace him will show. But whereas David Steel secured very little in return for propping up the Callaghan government in the late Seventies, Mr Ashdown managed to secure from Mr Blair a proportional electoral system for the European elections, the last through which Mr Ashdown leads his party; the promise of a referendum on electoral reform for the House of Commons; and places on a joint cabinet committee on what is now much more than constitutional reform.
In this course, he was helped since 1994 by dealing with a leader, in Mr Blair, who liked him personally, who thought the same way about most political and ideological issues, and who had fewer tribal roots in, and hang-ups about, his party than any of his predecessors. But Mr Ashdown's part in this process should not be under-estimated. A month after the 1992 election, Mr Ashdown made an important and lightly coded speech in Chard, Somerset, in which he sketched out a route map for abandonment of what had been a fiction since Mrs Thatcher's election in 1979 - that the third party was prepared to prop up a Tory government in a coalition. The word for it was "equidistance" between Labour and the Tories, and it was quietly buried in May 1995.
But what showed Mr Ashdown to be a bigger figure than his critics suggested was his reaction to Mr Blair's leadership. Mr Blair was suddenly the new kid on the centrist block; for a time it looked as if a Blair-led Labour party would eclipse the Liberal Democrats.
At this point Mr Ashdown could have either given up politics, or eked out the rest of his political career in carping from the sidelines. Instead, he saw quicker than many in his own party that Mr Blair was a hegemonic figure and that the best route to improving his own party's standing lay in eliminating wasteful conflict with Labour for the sake of it, while at the same time preserving his own party's identity.
The 1995 Littleborough and Saddleworth by-election was a turning point; while it showed that there were indeed no "no-go" areas for Labour, it also showed that the Liberal Democrats, whose candidate, Chris Davies, withstood a vicious assault from Labour to win - were not going to be eliminated by Blairism. As a result, he was able to enter the friendlier positioning towards Labour which started soon afterwards from a position of some strength rather than total weakness.
The fruits were tangible; spontaneous tactical anti-Tory voting across the country, and the Cabinet links since the general election. And given that he decided before the election to depart in this Parliament, it is easy to see why he has been pressing so urgently for further, closer links - a joint statement with Mr Blair about working together in November, and the extension of the joint cabinet committee process to foreign affairs last week.
He has had a strong marriage to long-suffering Jane, which survived the affair he was revealed to have had with a secretary in the run-up to the 1992 election. In a coup of media management, Ashdown went candidly public on it, pre-empting a good deal of hostile press coverage, and in the process he became one of the first politicians to demonstrate that the British electorate is more interested in their professional performance than their sex lives.
Now a grandfather, by retiring he will be able to repay his family for a decade of lost time. Invariably hyperactive, in 1992 he toured the UK, staying in the homes of ordinary voters, from fishermen to single mothers in the inner city, and wrote of his experiences in the book Beyond Westminster. It was a way of raising his profile, of course, but it also reflected his view that there was more to politics than the House of Commons.
In his range of interests he stood out in the notoriously parochial political village for his energetic and sometimes unfashionable pursuit of causes in foreign affairs, notably for more consistent allied intervention in the Balkans. He has been - in a party with a much broader streak of Euro- scepticism than is often realised - consistently pro-European and pro- EMU; he has been surprisingly steadfast in believing that Mr Blair will call a referendum on EMU, a mechanism which he was the first party leader to advocate.
The question is what his departure, announced last night, will mean for the slow process towards realignment, closer links between the two parties, electoral reform, and possibly, in the long-term, coalition.
Mr Ashdown himself is convinced that all the building blocks are in place. But it is hard not to see it as a setback. Mr Ashdown has faced almost as many critics of the process in his own party as Mr Blair has in his.
Mr Ashdown always said he wanted to leave when people asked "Why is he going?" rather than "Why hasn't he gone?" In that sense, it is a good departure by a leader on a high note. But both he and Mr Blair will be hoping that he has not under-estimated his personal importance to their joint project.Reuse content