The New Forest, famed for its wild ponies, was unveiled as the UK's newest national park on Tuesday.
The ancient hunting grounds become the UK's smallest national park and the first in England for 50 years.
It will lead to added protection for rare species and habitats, supporters of the plan say.
Opponents worry that it will mean extra bureaucracy for residents and will bring more visitors than the area's amenities can support.
Rural Affairs Minister Alun Michael said it would preserve the "unique character" of the forest - situated between Southampton and Bournemouth.
"It takes its place alongside areas such as Dartmoor and the Lake District in the first rank of our protected areas.
"Like the existing parks it will have a vital role in conserving our natural and cultural heritage, and in balancing environmental priorities with those of communities.
"It needs to protect its unique character - valued by so many people, and acknowledged as a national treasure for nearly a thousand years - whilst remaining a working, living place with social and economic needs."
The New Forest National Park Authority will receive an annual government grant of about £3.5m, to be spent on conservation projects.
The last official national park set up in England was in Northumberland in 1956.
The New Forest is famous for its wild ponies
The Broads was the last area of the UK to come under the control of the National Parks Authority - in 1989 - but is not an official national park as it was set up using different legislation, the authority confirmed to BBC News.
The 250 square mile boundaries of the New Forest Park are much smaller than the area originally proposed two years ago, and now exclude the valley of the river Avon to the west of the forest and Dibden Bay to the east.
The bay was recently the scene of confrontation over rejected plans for a massive new container port.
The leader of the New Forest District Council, Melville Kendal, said local people had not asked for the park and that it had been a top-down process.
He said many residents were worried it could undermine the gradual change process managed locally which had evolved over hundreds of years.
But he promised to work with the new body, saying: "New Forest District Council will work closely with the new national park authority to ensure the smooth introduction of new regulations on this historic day."
Julian Lewis, Tory MP for New Forest East said: "What this does is remove a consensual system - a system of checks and balances - that has been in place for centuries and replaces it with a single overarching body."
New Forest commoners - 500 locals who hold ancient grazing rights - are concerned that these could be eroded.
But English Nature's chief executive Dr Andy Brown said: "This is history in the making. The National Park Authority is in a good position to take the New Forest forward in a way that will bring together wildlife, people and the local economy in an integrated and positive way."