Neil Kinnock will complete a political journey from fiery left-wing rebel MP to a seat in the Lords when he steps down as the European Commission's vice-president.
Neil Kinnock has vowed to be "a bloody old nuisance".
He has already indicated he is unlikely to enjoy a quiet retirement when he steps down from the commission in November.
His decision to enter the Lords has brought criticism from certain sections of the press who have branded him a "hypocrite".
He told a politics website last year: "I'm not even sure I'd go into a reformed House of Lords".
But speaking on the day he received his peerage, Mr Kinnock said he was persuaded to accept it so that he could help reform the House of Lords from within.
He told BBC Wales the Lords themselves would have to vote for change.
Inspired by his wife Glenys's work as an MEP in trying to tackle tragedies in the developing world, he now regards the Upper House as a good platform for campaigning.
"Because I've been such a good boy for 25 years, I've been so bloody respectable and responsible... I'm going to be a bloody old nuisance," he said.
"I want to make trouble for some people. Top of my list is Robert Mugabe."
Whatever he does, the 62-year-old will always have a place in Labour history for the crucial role he played in transforming the party.
Some within Labour still hate him for that. Others give him great credit, and say Tony Blair owes his predecessor an enormous debt of gratitude for beginning the party's long road to recovery.
Battle with militants
Mr Kinnock took over as Labour leader from Michael Foot after the party's battering at the hands of Margaret Thatcher in the 1983 general election.
Beginning his long career in mainstream UK politics in 1970, he served as MP for Bedwellty until 1983 when it became Islwyn, and he remained an MP until 1995.
When Labour returned to power in 1974, Mr Kinnock sided with left-wingers to
vote against Harold Wilson's package of spending cuts during the 1975 sterling
He also turned down the offer of a junior post from James Callaghan, on the grounds that the price of silence was not worth paying.
But he joined the shadow cabinet in 1980, speaking on education, with many starting to tip him as a future party leader.
Indeed, during the disastrous 1983 election campaign he was seen as one of Labour's few success stories.
Soon after becoming leader, he began what became one of the defining battles of his leadership - the long and bitter tussle with the hard left.
Mr Kinnock has been inspired by his wife's work as an MEP
In a famous conference speech in Bournemouth in 1985, and amid chaos in militant-controlled Liverpool, he took on the hard left, prompting uproar in the conference hall.
A series of expulsions followed as Mr Kinnock tried to take Labour back to the centre left, overseeing the reversal of policies on unilateral nuclear disarmament, pulling out of the European Union and large-scale nationalisation.
The battle came hand-in-hand with the rise of Peter Mandelson and efforts to portray Labour as a party of the mainstream. As militants were thrown out, in came the red rose.
'Vicious' attacks in press
Essentially, however, Mr Kinnock's leadership ended in failure.
Labour was expected to oust the Tories in 1992, but John Major was unexpectedly returned to power.
Labour blamed vicious attacks on their leader in the press; others said a famously triumphalist rally in Sheffield a few days before polling day had also played a big part.
Mr Kinnock himself still seethes at the way he was treated by the press. The "Welsh windbag" label stuck.
He resigned as party leader soon after the election, but remained an MP until 1995, when he became European commissioner for transport.
He became vice-president in 1999 with the testing responsibility for internal reform.
In March 1999 he was among the 20 commissioners who resigned - but returned the same year, promising to root out fraud and incompetence.
But last year he was dogged by a row over his handling of the whistle-blower controversy.
Former commission chief accountant Marta Andreasan was suspended in May 2002 after she complained that the EU budget was open to fraud and abuse.
Mr Kinnock said she was suspended not for whistle-blowing, but for failing to follow the EU's whistle-blowing procedures.
He is likely to take a prominent role in the referendum campaign on the European Constitution.
He joined the board of Britain in Europe in September, saying: "To influence we must be properly in. There is no such thing as outfluence."
And he will take over as head of the British Council, which promotes the UK's reputation for arts, science and education.
He has said he plans to watch more sport and theatre and see more of his grandchildren.
But he will find the time to be an activist, drawing attention to injustice in the UK and abroad.
"There is always a case for attacking evil and if you are in the position that I'll be in...[I'll] actually have the time to do it. A lot of full-time politicians haven't got the time to do it," he has said.