How RHI 'scandal' sparked a row that brought down the Assembly
November 2012: An initiative to reduce Northern Ireland's carbon emissions called the Renewable Heating Incentive is announced by then Enterprise Minister Arlene Foster. It financially supports businesses, public sector and other non-domestic organisations to meet the cost of more environmentally-friendly technologies. Eligible applicants will be entitled to help for 20 years.
Autumn 2013: A whistleblower contacts Mrs Foster and asks for a meeting to raise concerns.
January 2015: A formal re-approval of the scheme due from the Department of Finance is overlooked as a result of a "combination of staff changes and an administrative oversight". Meanwhile, RHI applications rise.
february: It is claimed RHI will overspend by at least £460m over a 20-year period. Mrs Foster's successor as Enterprise Minister, Jonathan Bell, announces his intention to close RHI to new applications. Internal investigation into scheme gets under way.
july: In a damning report the Audit Office says "serious systemic failings" in the scheme will cost the NI budget hundreds of millions. It reveals a farmer will make £1m for heating an empty shed.
october: Stormont's Public Accounts Committee (PAC) call the mishandling of the RHI scheme "one of the biggest scandals" since devolution.
november: With the realisation the funding available for applicants is uncapped, Stormont tightens the rules. But a massive late surge of 900 applications is received before changes can be made. The PAC is told that a £405m hole will have to be plugged over the 20-year lifetime of the RHI.
december 15: In an extraordinary TV interview, Mr Bell claims advisers attempted to remove Arlene Foster's name from documents linked to RHI while two senior special advisers "were not allowing this scheme to be closed" as costs began to spiral out of control.
Mrs Foster responds by saying that if papers were altered "it wasn't on my say-so" and DUP special advisers Timothy Johnston and Andrew Crawford say they never sought to keep the RHI scheme open against the wishes of the minister.
december 16: Deputy First Minister Martin McGuinness calls for the DUP leader to stand aside from her role as First Minister.
january 4, 2017: Arlene Foster again insists she will not stand down over the RHI scandal and says some calls for her to do so are "misogynistic".
january 9: Martin McGuinness announces his resignation as deputy First Minister in protest at Mrs Foster's refusal to step aside during an investigation into the RHI.
april 2018: Mrs Foster admits to the RHI Inquiry that she didn't read the legislation which set up RHI. She feels she doesn't bear personal responsibility for the scheme, even though it was set up on her watch as a minister.
September 7: Mr Bell claims that he was bullied into keeping RHI open by Mrs Foster and says he was the victim of a DUP smear campaign.
september 10: Mr Bell's former special adviser claims the minister got so drunk in a New York pub he was asked to leave. He says that it was DUP policy to introduce RHI cost controls as late as possible. He claims that senior DUP spad Timothy Johnston wielded power over elected politicians.