Scotland was taken by surprise yesterday with the news that Nicola Sturgeon is to stand down as first minister after more than eight years in the post.
Criticism of the SNP leader on a number of issues has been steadily mounting in recent months, but few people could have seen her announcement coming.
The search for a new first minister is now beginning.
The SNP's national executive committee will meet tonight to draw up a timetable for the leadership race.
The BBC says that, with no obvious successor, the party's first leadership contest in nearly 20 years could see a debate on future direction and strategy.
Possible replacements include Deputy First Minister John Swinney, Kate Forbes - who was Finance Secretary before her maternity leave - and Constitution Secretary Angus Robertson. Health Secretary Humza Yousaf and Justice Secretary Keith Brown have also been suggested as potential candidates, but no one has yet signalled their intention to stand.
'Committed, dedicated and passionate'
Liz Cameron, chief executive of Scottish Chambers of Commerce, said that Ms Sturgeon had been a committed, dedicated and passionate public servant for Scotland.
But the business leader also added: "As we look ahead to whoever becomes the next first minister, a full in-tray of issues requiring immediate attention awaits them.
"Urgency, action and partnership will be the watchwords from the business community. These will be essential parameters to create a business environment in Scotland which is growth-led and competitive.
"We will continue to work with the next first minister as genuine partners as we collectively grow the economy as well as correcting regulatory policies which are not practically working for businesses."
Ms Sturgeon plans to remain in office until her successor is elected.
She made yesterday's announcement at a hastily-convened news conference at her official Edinburgh residence, Bute House, but insisted it was a decision she had been weighing up for some time.
Making way
The first minister said that, in order to serve well, a politician needed to accept when it was time to make way for someone else.
"In my head and in my heart I know that time is now. That it's right for me, for my party and my country," she said.
Ms Sturgeon said her departure was not in response to the "latest period of pressure", which has included controversies over gender-recognition reforms, trans prisoners and strategy on independence.
She emphasised the huge pressures and sacrifices that came with serving in high office, adding: "I am a human being as well as a politician."
She intends to remain an MSP until at least the next Holyrood election.
The party's ruling body will now also have to decide on whether to go ahead with a special conference due to take place in March to discuss Ms Sturgeon's strategy of using the next general election as a de facto independence referendum.
Pause conference call
The SNP's Westminster leader Stephen Flynn, who ruled himself out of the leadership contest, has called for the conference to be paused until a new leader is elected.
Ms Sturgeon rose to power unopposed after the independence referendum in 2014, taking over from Alex Salmond who decided to resign following the vote to remain part of the UK.
She is the longest-serving first minister and the first woman to hold the position. She has worked as an MSP since the Scottish parliament was opened in 1999.