Leighton Andrews rejoins cabinet in reshuffle
First Minister Carwyn Jones has carried out a reshuffle of his ministerial team, reducing the size of the cabinet by one post.
Leighton Andrews has rejoined the cabinet as minister for public service, 15 months after he resigned.
He will be responsible for delivering local government changes in a newly created post.
Jeff Cuthbert and John Griffiths both leave the cabinet.
Housing Minister Carl Sargeant moves to natural resources and Lesley Griffiths to communities and tackling poverty.
Mr Andrews said he was "pleased" to be rejoining the cabinet.
Speculation about his return intensified after he was seen leaving Welsh government offices at lunchtime.
Mr Andrews resigned as education minister in June 2013 following a row over his defence of a school in his Rhondda constituency which faced closure under his own surplus places policy.
His new job will be to deliver major changes in the landscape of local government, with the Williams Commission recommending mergers between councils and a reduction in number from 22 to 10 or 12.
Of the two cabinet departures, John Griffiths had been a minister since 2011. Mr Sargeant takes over his natural resources brief while his culture and sport work will be carried out by a deputy minister.
Mr Jones said Mr Griffiths had "made his mark" in a number of Welsh government roles, notably as Counsel General and "delivering the pioneering Active Travel Bill".
Jeff Cuthbert is standing down as communities minister, ahead of his decision not to stand for re-election as Caerphilly AM in 2016. He said he was "sad to go but grateful for a chance to serve".
The first minister said: "Jeff did great work on tackling poverty, shaping the Future Generations Bill and mitigating worst effects of welfare reform".
Mark Drakeford, Jane Hutt, Edwina Hart and Huw Lewis are all staying in their jobs, while Janice Gregory retains her role as chief whip.
Analysis by Tomos Livingstone, BBC Wales political correspondent
All eyes might be on Scotland, but in Cardiff Bay at least politics is going on as normal.
This was a major reshuffle with one main objective - bring back one of Welsh Labour's big beasts to the front line, and send a signal to local councils that the Welsh government is serious about forcing them to merge.
So Leighton Andrews, the man who ran Carwyn Jones's leadership campaign in 2009 is back. His misdemeanour 18 months ago - campaigning to keep a school open in his own constituency against his own guidelines as Education Minister - is forgiven, if not forgotten. He now has a new job title - Minister for Public Service Reform - and licence to force through those changes to local government.
It won't be easy - many council leaders aren't exactly overjoyed at the prospect of mergers. But as education minister he had a reputation for bashing heads together and making it very clear if things weren't to his liking. This is going to be a bumpy ride.
Elsewhere there's continuity, with Edwina Hart, Huw Lewis and Mark Drakeford staying in post. Jeff Cuthbert and John Griffiths are leaving the cabinet, and Mr Cuthbert's old job, Culture Minister, has been downgraded to a deputy minister job. Gwenda Thomas is also leaving after lengthy services as deputy health and social services minister.
This wasn't a chance to bring in new faces and freshen up the cabinet - it was a reboot to make sure everyone's clear about the Welsh government's priority over the coming weeks and months.
The reshuffle announcement came on Twitter at 13:00 BST.
The news also came as a surprise to cabinet members ahead of a return to Cardiff Bay after the summer recess for assembly members on Monday.
The previous change, an enforced one, was in July when Alun Davies was sacked as natural resources minister for pressurising civil servants for private information on opposition AMs.
His responsibilities were split between Mrs Hart, Deputy Agriculture Minister Rebecca Evans and Mr Griffiths.
The Welsh Conservatives responded to Thursday's developments by saying the last reshuffle "was a botched sticking plaster following the sacking of Alun Davies".
The cabinet comings and goings:
Carwyn Jones AM - First Minister
Leighton Andrews AM - rejoins cabinet, new post - Minister for Public Services
Jeff Cuthbert AM - leaves cabinet - was Minister for Communities and Tackling Poverty.
Mark Drakeford AM - staying in post - Minister for Health and Social Services.
John Griffiths AM - leaves cabinet - was Minister for Culture and Sport, post downgraded.
Lesley Griffiths AM - becomes Minister for Communities and Tackling Poverty - was Minister for Local Government and Government Business.
Edwina Hart AM - staying in post - Minister for Economy, Science and Transport.
Jane Hutt AM - staying in post but with added responsibility for government business - Minister for Finance.
Huw Lewis AM - staying in post - Minister for Education and Skills.
Carl Sargeant AM - becomes Minister for Natural Resources - was Minister for Housing and Regeneration.
Theodore Huckle QC - Counsel General.
Rebecca Evans AM, - becomes Deputy Minister for Farming and Food - was Deputy Minister for Agriculture and Fisheries.
Vaughan Gething AM - becomes Deputy Minister for Health - was Deputy Minister for Tackling Poverty.
Julie James AM - becomes Deputy Minister for Skills and Technology
Ken Skates AM - becomes Deputy Minister for Culture, Sport and Tourism under Edwina Hart - was Deputy Minister for Skills and Technology.
Gwenda Thomas AM - stepping down - was Deputy Minister for Social Services.
Source: Welsh government