This week Jeremy Corbyn steps down after five years as Labour leader.
He ran for the top job never expecting to win and went on to oversee one of the most tumultuous and controversial chapters in his party's history.
On the one measure that matters – the winning of power – he failed comprehensively, losing two general elections.
Many in the Labour will want to write his time in charge out of the history books. Others will claim he transformed his party and gave Labour back its soul.
So how did he fare?
If the purpose of a political party is to win power then Labour failed abjectly under Corbyn.
Although he surprised his detractors in the 2017
general election, Labour was still 57 seats short of the majority needed to govern.
The 2019 election was even worse which saw Corbyn lead his party to its worse result since 1935.
The dismal run of form also saw Labour lose 84 seats in 2019 local elections and 384 in the 2017 local elections.
Party management From the beginning Corbyn struggled to impose his command on the Parliamentary Party.
He only scraped on to the ballot paper after MPs loaned him their vote to 'broaden the debate.' Few thought he would win.
Having been a serial rebel under previous leaders he lacked the authority to whip his own backbenchers into line.
In 2016 dozens of frontbenchers resigned prompting an abortive leadership challenge led by Owen Smith.
The party membership rallied behind their leader but it left Labour bruised and divided.
And the warring continued at a local level as Corbyn supporters tried to deselect MPs who were deemed disloyal to the cause.
Corbyn's failure to tackle anti-Semitism is by far the biggest stain on his leadership. Labour became the second party after the BNP to be investigated by the Equality and Human Rights Commission for failing to root out anti-Jewish hate.
Apologists for the Labour leader said the number of cases of proven anti-semitism was a fraction of the party membership.
But Corbyn was too slow to stamp down on the hatred and abuse by supporters acting in his name.
The failure saw Jewish MPs such as Louise Ellman and Luciana Berger driven from the party and the Chief Rabbi warn that Jewish people would not be safe if Labour won power under Corbyn.
Misjudged response to Salisbury poisonings
Corbyn is rightly praised for empathy for those who have been hard done by but he often appeared to be out of touch with voters, including many traditional Labour voters, who like the flag, forces and family – they are patriotic, proud of the Armed Forces and fond of the Royals.
Fairly or unfairly he was accused early on in his leadership of failing to sing the National Anthem.
For many voters the defining moment was his response to the Skripal poisonings when he was initially reluctant to blame the Russians.
Struggled with Brexit
Any Labour leader would have found it difficult to plot a path through the thickets of the Brexit debate.
As a lifelong Eurosceptic, Corbyn found himself out of step not just with the majority of his MPs but the pro-EU party membership.
In trying to keep the party together he ended up with a compromise position that pleased almost no one.
In the December 2019 he undermined his credentials as a conviction politician by promising a second referendum while refusing to say which way he would vote.
Transformed Labour The Labour Corbyn bequeaths the new leader is very different to the one he inherited.
The triangulation of the Tony Blair years which saw the party shadow many Tory economic policies was ditched for a more radical, socialist agenda.
Corbyn and his supporters campaigned on an ambitious, some would argue too ambitious, manifesto that pledged to renationalise swathes of the economy, scrap tuition fees and invest in schools, health and education.
Whoever wins the leadership is unlikely to turn back the clock.
Built a mass membership party
When Corbyn became leader in 2015 Labour's membership stood at 190,000.
Five years later and can now boast more than 500,000 members – one of the largest political movements in the world.
This mass membership has given Labour an army of supporters on the ground and brought in vital funds.
Many of those who joined were young people who were energised by Corbyn's message of change.
But it has also caused tensions at a local level with more radical members finding themselves at odds with long-standing supporters from the Tony Blair and Gordon Brown years.
Championed the underdog Corbyn won the leadership promising a “gentler, kinder, politics.” While not all his followers lived up to this ideal, the party leader won plaudits for the way he spoke up for those in hardship
His citing of real people's experiences at Prime Minister's Questions was further proof of his wish to do politics differently.
Tory MPs often scoffed when he championed welfare claimants or spoke up for bus travellers but the showed Corbyn had a better grasp of life outside Westminster than many gave him credit for.
This was especially the case when he comforted the victims of the Grenfell fire in 2017, showing an empathy Theresa May failed to display.
With no previous experience of running anything the responsibility of leadership did not sit easily on Corbyn's shoulders.
His instinctive loyalty to his fellow leftwingers often saw colleagues promoted to positions beyond their ability.
Other MPs spoke of their frustration at trying to arrange meetings or get decisions from the leader's office
Distrust between the various factions saw infighting not just within the Parliamentary Labour Party but between the leader's office and the Party HQ.