The biggest moments of the RHI scandal
THE scandal surrounding the Renewable Heat Incentive (RHI) scheme exposed a litany of problems in Stormont's power-sharing system and ultimately led to its three-year collapse.
Here are some of the key moments from the controversy and the subsequent public inquiry which had long dominated politics in Northern Ireland:
While RHI's inherent flaws were revealed five months earlier in an Audit Office report and the Public Accounts Committee had begun its own enquiries, it was BBC's Spotlight programme which distilled the scandal to the wider public.
Aired on the evening of December 6 2016, it was the striking footage of journalist Conor Spackman tossing cash into a fire which effectively illustrated the scale of Stormont's blunders – and incensed viewers.
The programme also included details of a whistleblower email sent directly to DUP leader and First Minister Arlene Foster, escalating the controversy.
Jonathan Bell breaks ranks
Nine days later as the scandal raged, DUP MLA and ex-enterprise minister Jonathan Bell gave an explosive BBC Nolan Show interview in which he turned on his party colleagues including Mrs Foster.
The interview began with the extraordinary sight of the politician kneeling in a TV studio as two men laid their hands on his back in prayer.
When Mrs Foster became aware of the pre-recorded interview, she demanded a right of reply and so was also interviewed.
Mr Bell alleged that Mrs Foster had shouted at him to keep the RHI scheme open, but Mrs Foster denied this and claimed Mr Bell was a "very aggressive individual" and had "used his physical bulk to stand over me".
The unprecedented political showdown was watched by more than half of Northern Ireland's TV viewing audience at the time.
Martin McGuinness resigns
After Mrs Foster refused to stand aside as First Minister while the scandal was investigated, Sinn Féin's Martin McGuinness resigned as Deputy First Minister.
In a press conference called at short notice in his office in Parliament Buildings on January 9 2017, Mr McGuinness said it was "time to call a halt to the DUP's arrogance".
Aside from the political significance of his decision – triggering the collapse of power-sharing – his gaunt appearance shocked many, as he not been seen publicly for some weeks.
It revealed the serious illness which would claim his life less than three months later.
Arlene Foster: 'I'm accountable but I'm not responsible'
As the minister who launched RHI, the DUP leader's attendances at the public inquiry set up to investigate the controversy were among the most closely watched.
A key consideration has been what level of responsibility she holds for the many failings.
Mrs Foster admitted she had not even read the RHI regulations when she brought them to the assembly for approval, saying she "probably would have only read the explanatory note".
She acknowledged the controversy was a "matter of deep regret for me politically and personally", but insisted that officials should have given her more information and flagged up any issues.
Her evidence broadly consisted of denying claims made by others against her, and being unable to recollect specifics.
On the actions of her special adviser (Spad) Andrew Crawford, who the inquiry heard passed sensitive RHI information to relatives, Mrs Foster said: "I'm accountable.. but I'm not responsible."
She defended Mr Crawford later being employed in a part-time role with the DUP on Brexit issues.
Breakfast at Tiffany's
During the inquiry hearings, the more mundane details of what went wrong with RHI were at times overshadowed by the salacious allegations and details of dysfunctional relationships at the top of Stormont.
Former DUP enterprise minister Jonathan Bell was accused by his ex-Spad Timothy Cairns of bullying, swinging a punch at him and trying to break his finger – claims which Mr Bell denied.
It was also alleged that Mr Bell was asked to leave a New York pub during a ministerial trip after he became intoxicated and fell asleep twice.
He sang Deep Blue Something hit single Breakfast at Tiffany's "at full volume" while being helped back to his hotel, Mr Cairns claimed.
Mr Bell also made reference to an allegation of "sexual misbehaviour of two DUP ministers" but was stopped from elaborating by the inquiry chair Sir Patrick Coghlin.
'Sensitive to criticism'
The RHI inquiry revealed not only a series of issues at a political level, but also in the operations of the civil service, including concerns about a culture of secrecy.
Stormont's chief civil servant David Sterling admitted that some meetings were deliberately not minuted to avoid disclosures through Freedom of Information legislation.
He said the DUP and Sinn Féin were "sensitive to criticism" and it was "safer" not to have a record which might be released through FOI requests.
His startling comments prompted a separate investigation by transparency watchdog the Information Commissioner's Office.