People in Cornwall will get their first chance to vote for members of the new unitary "super council" at the 4 June ballot.
Members will be elected in a total of 123 wards - more than any other English council at this poll.
Cornwall Council has replaced six borough and district authorities, as well as the former county council.
It has an annual budget of nearly £440m and a staff of more than 22,000, making it the biggest single employer in the area.
And it is hoped the unified council will provide millions of pounds in savings for taxpayers.