Plaid Cymru's national council signalled the start of an historic coalition with Labour to run the Welsh Assembly Government.
The party's delegates voted overwhelmingly 225-18 in favour of the deal in a meeting at Pontrhydfendigaid, in Ceredigion.
Ynys Mon AM Ieuan Wyn Jones will become deputy first minister plus other seats in the cabinet which will be announced next week.
A copy of the One Wales agreement between Labour and Plaid Cymru can be viewed here.
